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Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level

PHYSICS 9702/11

Paper 1 Multiple Choice October/November 2015

1 hour

Additional Materials: Multiple Choice Answer Sheet Soft clean eraser Soft pencil (type B or HB is recommended)

READ THESE INSTRUCTIONS FIRST

Write in soft pencil.

Do not use staples, paper clips, glue or correction fluid.

Write your name, Centre number and candidate number on the Answer Sheet in the spaces provided unless this has been done for you.

DO NOT WRITE IN ANY BARCODES.

There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D.

Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet.

Read the instructions on the Answer Sheet very carefully.

Each correct answer will score one mark. A mark will not be deducted for a wrong answer.

Any working should be done in this booklet.

Electronic calculators may be used.

2

© UCLES 2015 9702/11/O/N/15

Data

speed of light in free space, c = 3.00 × 108 m s–1

permeability of free space, µ0 = 4π × 10–7

H m–1

permittivity of free space, ε0 = 8.85 × 10–12

F m–1

(0

4

1

επ

= 8.99 × 109 m F–1)

elementary charge, e = 1.60 × 10–19 C

the Planck constant, h = 6.63 × 10–34 J s

unified atomic mass constant, u = 1.66 × 10–27 kg

rest mass of electron, me = 9.11 × 10–31 kg

rest mass of proton, mp = 1.67 × 10–27 kg

molar gas constant, R = 8.31 J K–1 mol–1

the Avogadro constant, NA = 6.02 × 1023 mol–1

the Boltzmann constant, k = 1.38 × 10–23 J K–1

gravitational constant, G = 6.67 × 10–11 N m2

kg–2

acceleration of free fall, g = 9.81 m s–2

3

© UCLES 2015 9702/11/O/N/15 [Turn over

Formulae

uniformly accelerated motion, s = ut + 2

2

1at

v

2 = u

2 + 2as

work done on/by a gas, W = p∆V

gravitational potential, φ = –

r

Gm

hydrostatic pressure, p = ρ gh

pressure of an ideal gas, p = V

Nm3

1 <c

2>

simple harmonic motion, a = – ω

2x

velocity of particle in s.h.m., v = v0 cos ωt

v = ± ω )( 22

0xx −

electric potential, V = r

Q

04 επ

capacitors in series, 1 / C = 1 / C1 + 1 / C2 + . . .

capacitors in parallel, C = C1 + C2 + . . .

energy of charged capacitor, W = QV2

1

resistors in series, R = R1 + R2 + . . .

resistors in parallel, 1 / R = 1 / R1 + 1 / R2 + . . .

alternating current/voltage, x = x0 sin ωt

radioactive decay, x = x0 exp(–λt)

decay constant, λ =

2

1

0.693

t

4

© UCLES 2015 9702/11/O/N/15

1 What is the unit of weight in terms of SI base unit(s)?

A kg m s–1 B kg m s–2 C N D J m–1 2 At temperatures close to 0 K, the specific heat capacity c of a particular solid is given by c = bT

3, where T is the thermodynamic temperature and b is a constant characteristic of the solid.

The SI unit of specific heat capacity is J kg–1 K–1.

What is the unit of constant b, expressed in SI base units?

A m2 s

–2 K–3

B m2 s–2

K–4

C kg m2 s–2

K–3

D kg m2 s–2

K–4 3 In making reasonable estimates of physical quantities, which statement is not correct?

A The frequency of sound can be of the order of GHz.

B The wavelength of light can be of the order of 600 nm.

C The Young modulus of a metal can be of the order of 1011 Pa.

D Beta particles are associated with one unit of negative charge. 4 A calibration graph is shown for an ammeter whose scale is inaccurate.

0.6

0.5

0.4

0.3

0.2

0.1

00 0.1 0.2 0.3 0.4 0.5 0.6

current / mA

ammeterreading / mA

Two readings taken on the meter at different times during an experiment are 0.13 mA and 0.47 mA.

By how much did the current really increase between taking the two readings?

A 0.30 mA B 0.35 mA C 0.40 mA D 0.44 mA

5


5 Four identical rods have a square cross-section. The rods are placed side by side and their total width is measured with vernier calipers, as shown.

vernier calipers

four squarecross-section rods

1

The measurement is (8.4 ± 0.1) mm and the zero reading on the calipers is (0.0 ± 0.1) mm.

What is the width of one rod?

A (2.10 ± 0.025) mm

B (2.10 ± 0.05) mm

C (2.1 ± 0.1) mm

D (2.1 ± 0.2) mm

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6 A light-meter measures the intensity I of the light incident on it. Theory suggests that I varies inversely as the square of the distance d.

light-meter

d

Which graph of the results supports this theory?

d

I

0

A

d

I

0

B

d 2

I

0

C

1d 2

I

0

0 0

0 0

D

7


7 One of the equations of uniformly accelerated motion is shown.

s = ut + 2

2

1 at

Apparatus is arranged to record the time t taken for a marble to fall between two light gates connected to timers. The marble touches the stop before it is released. The vertical distance s between the light gates is measured.

s

fixed stop

fixed light gate 1connected to timer

movable light gate 2connected to timer

marble

Which graph does not show a correct relationship when light gate 2 moves up to light gate 1 which is fixed?

s / m

t / s

A

/ m s–1

t / s

B

u / m s–1

t / s

C

a / m s–2

t / s

D

st

00

00

00

00

8

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8 A stone is dropped from a height of 20 m above water. The graph shows the variation with time of the velocity of the stone.

0 2 40

5

20

time / s

velocity / m s–1

Which statement describes the approximate position of the stone four seconds after it is dropped?

A It is at a distance of 10 m above the surface of the water.

B It is at a distance of 10 m below the surface of the water.

C It is at a distance of 20 m below the surface of the water.

D It is at a distance of 30 m below the surface of the water. 9 The water surface in a deep well is 78.0 m below the top of the well. A person at the top of the

well drops a heavy stone down the well.

Air resistance is negligible. The speed of sound in the air is 330 m s–1.

What is the time interval between the person dropping the stone and hearing it hitting the water?

A 3.75 s B 3.99 s C 4.19 s D 4.22 s

9


10 A golf ball is hit by a club. The graph shows the variation with time of the force exerted on the ball by the club.

force

time00

Which quantity, for the time of contact, cannot be found from the graph?

A the average force on the ball

B the change in momentum of the ball

C the contact time between the ball and the club

D the maximum acceleration of the ball 11 A glider of mass 1500 kg is launched from rest on a straight and level track using a catapult. The

graph shows the variation with time of the resultant force.

10.0

8.0

6.0

4.0

2.0

0

force / kN

time / s

0 5 10 15 20 25 30 35 40

What is the speed of the glider when the resultant force acting on it reaches zero?

A 133 m s–1 B 200 m s–1 C 250 m s–1 D 267 m s–1 12 Which statement about a ball that strikes a tennis racket and rebounds is always correct?

A The total kinetic energy of the ball is conserved.

B The total kinetic energy of the system is conserved.

C The total momentum of the ball is conserved.

D The total momentum of the system is conserved.

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13 In which example is it not possible for the underlined body to be in equilibrium?

A an aeroplane climbs at a steady rate

B an aeroplane tows a glider at a constant altitude

C a speedboat changes direction at a constant speed

D two tug boats tow a ship into harbour 14 Two blocks X and Y are falling through a vacuum in a uniform gravitational field, as shown.

X

Y

directionof motion

Block X has weight 2w.

Block Y has weight w.

The blocks do not move apart.

Which value best represents the force exerted by block X on block Y?

A 0 B w C 1.5w D 2w 15 A gas is contained inside a sealed syringe, as shown.

graduated gas syringe

gas

The volume of gas at room temperature is 2.0 cm3.

Atmospheric pressure is 101 kPa.

What is the work done by the gas when it is heated and expands to a volume of 6.0 cm3?

A 404 µJ B 404 mJ C 404 J D 404 kJ

11


16 A combined heat and power (CHP) station generates electrical power and useful heat. The diagram shows the input and output for a CHP station.

input powerfrom fuel

wasted power60 MW

useful heating power160 MW

useful electrical power100 MW

What is the efficiency of the CHP station for producing useful power?

A 31% B 38% C 50% D 81% 17 In ‘normal driving conditions’, an electric car has a range of 150 km. This uses all of the 200 MJ

energy stored in its batteries.

With the batteries initially fully charged, the car is driven 100 km in ‘normal driving conditions’. The batteries are then recharged from a household electrical supply delivering a constant current of 13.0 A at a potential difference (p.d.) of 230 V.

What is the minimum time required to recharge the batteries?

A 0.95 hours

B 12.4 hours

C 18.6 hours

D 27.9 hours 18 A fixed amount of gas is reduced in volume at a constant temperature.

What is the reason for the increase in pressure of the gas?

A The average distance travelled between collisions by the gas molecules is increased.

B The average intermolecular attractive force between the gas molecules is decreased.

C The average speed of the gas molecules is increased.

D The frequency of the collisions of the gas molecules with the walls of the container is increased.

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19 A U-tube closed at one end contains mercury. Air at a pressure of 5.0 × 104 Pa is trapped at the

closed end. The other end is open to the atmosphere and is fitted with a piston of mass 5.0 kg

and cross-sectional area 5.0 × 10–4 m2.

The density of mercury is 13 600 kg m–3 and atmospheric pressure is 1.01 × 105 Pa.

mercury

harea

5.0 × 10–4 m2

piston of mass5.0 kg

trapped air atpressure 5.0 × 104 Pa

What is the height h of the mercury column?

A 37 cm B 44 cm C 74 cm D 110 cm 20 A known tensile force acts on a wire. The wire does not exceed its elastic limit.

Which two measurements enable the strain of the wire to be calculated?

A the unstretched length of the wire and the cross-sectional area of the wire

B the unstretched length of the wire and the extension of the wire

C the Young modulus of the wire’s material and the extension of the wire

D the Young modulus of the wire’s material and the unstretched length of the wire 21 The Young modulus of steel is determined using a length of steel wire and is found to have the

value E.

Another experiment is carried out using a wire of the same steel, but of half the length and half the diameter.

Which value is obtained for the Young modulus in the second experiment?

A 2

1 E B E C 2E D 4E

13


22 The graph shows the variation with stress of the strain of a material as it is extended elastically.

strain

stress0

0

Why is the strain energy per unit volume of the material not the area under the graph?

A The axes are the wrong way round.

B The graph is not a straight line.

C The graph is strain-stress instead of extension-force.

D The material is polymeric. 23 A wire has a final length of 6.0 m after undergoing a strain of 200%.

What is the original length of the wire?

A 1.5 m B 2.0 m C 3.0 m D 4.0 m 24 A sound wave is displayed on the screen of a cathode-ray oscilloscope, as shown.

The time-base setting is 0.50 ms per division.

What is the frequency of the sound wave?

A 250 Hz B 500 Hz C 670 Hz D 1300 Hz

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25 Part of a car was damaged by heating when, on a sunny day, the car was left in front of a curved mirrored building which focussed reflected sunlight onto the car.

Which statement about sunlight correctly explains this observation?

A Sunlight contains infra-red radiation.

B Sunlight contains ultraviolet radiation.

C Sunlight is a longitudinal progressive wave which carries energy.

D Sunlight is a transverse standing wave which carries energy. 26 A student sets up an experiment to investigate double-slit interference of light but finds that the

interference fringes observed on the screen are too close to each other to be distinguished.

s

doubleslit

screensingleslit

red filter

lightsource

Which change would help the student to distinguish the fringes?

A decrease the distance s between the two slits

B increase the width of each slit

C move the screen closer to the light source

D use a blue filter instead of a red filter 27 Ships have been damaged by water waves with large amplitudes. These waves could have been

formed by adding the displacements of smaller waves.

Which term describes this phenomenon?

A diffraction

B polarisation

C refraction

D superposition

15


28 Water waves of wavelength λ are diffracted as they pass through a gap of width d in a barrier.

Which combination of wavelength and gap width would produce the greatest angle of diffraction?

gap width wavelength

A 2

1 d 2λ

B 2

1 d 2

1 λ

C 2d 2λ

D 2d 2

1 λ

29 Two horizontal parallel plate conductors are separated by a distance of 20 mm in air. The upper

plate is earthed and the potential of the lower plate is +100 V.

20 mmP

0 V

+100 V

What is the electric field strength at point P midway between the plates?

A 5000 V m–1 downwards

B 5000 V m–1 upwards

C 10 000 V m–1 downwards

D 10 000 V m–1 upwards

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© UCLES 2015 9702/11/O/N/15

30 Three parallel metal plates of the same area are fixed with a separation of 2.0 cm between the top plate and the centre plate, and 1.0 cm between the centre plate and the bottom plate. The top plate is held at a potential of +500 V, the middle plate at +200 V and the bottom plate is earthed, as shown.

2.0 cm

1.0 cm

+500 V

+200 V

0 V

X

Y

What is the value of the ratio Yat electron an on force of magnitude

X at electron an on force of magnitude?

A 0.75 B 1.00 C 1.25 D 1.50 31 The diagram shows a graph.

00

y-axis

x-axis

For a uniform metallic wire, what could the graph not represent?

y-axis x-axis

A current potential difference

B resistance length

C resistance temperature in °C

D potential difference current

32 An iron wire has length 8.0 m and diameter 0.50 mm. The wire has resistance R.

A second iron wire has length 2.0 m and diameter 1.0 mm.

What is the resistance of the second wire?

A 16

R B

8

R C

2

R D R

17


33 The Atlantic torpedo is a large electric fish capable of generating a voltage of 220 V between its tail and its head. This drives a pulse of current of 15 A lasting for a time of 2.0 ms. The fish produces 200 pulses per second.

What is the average power output of the fish?

A 33 W B 1.3 kW C 3.3 kW D 6.6 kW 34 A thermistor and another component are connected to a constant voltage supply. A voltmeter is

connected across one of the components. The temperature of the thermistor is then reduced but no other changes are made.

In which circuit will the voltmeter reading increase?

A B

C D

VV

V V

18

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35 A 110 V d.c. supply is connected to a heater, a fuse and a switch, as shown.

F1 F2 switchfuse

heater110 VS+

S–

Owing to a fault in the system, power is not supplied to the heater. A technician diagnoses the fault using a voltmeter.

He closes the switch and connects his meter between the positive supply terminal S+ and the fuse terminal F2. The voltmeter reads 110 V.

Which diagnosis is correct?

A The fuse has melted.

B The fuse has not melted and there is a short circuit in the heater.

C The fuse has not melted and there is no path for current through the heater.

D The fuse has not melted and the switch has operated correctly. 36 The diagram shows a potentiometer and a fixed resistor connected across a 12 V battery of

negligible internal resistance.

output

12 V

20 Ω

20 Ω

The fixed resistor and the potentiometer each have resistance 20 Ω. The circuit is designed to provide a variable output voltage.

What is the range of output voltages?

A 0 – 6 V B 0 – 12 V C 6 – 12 V D 12 – 20 V

19

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37 Radioactive decay is random.

What is meant by the term random?

A The decay of a nucleus can be predicted.

B The decay of a nucleus is unaffected by pressure.

C The decay of a nucleus is unaffected by temperature.

D The nucleus has a constant probability of decay per unit time. 38 The nuclei of the isotopes of an element all contain the same number of a certain particle.

What is this particle?

A electron

B neutron

C nucleon

D proton 39 Which statement about nuclei is correct?

A Different isotopic nuclei have different proton numbers.

B For some nuclei, the nucleon number can be less than the proton number.

C In some nuclear processes, mass-energy is not conserved.

D Nucleon numbers of nuclei are unchanged by the emission of β-particles. 40 The diagram shows part of a radioactive decay chain in which the nuclide thorium-232 decays by

α-emission into radium-228. This nuclide is also unstable and decays by β-emission into a nuclide of actinium. This process continues.

232Th 228Ra XAc 228Th 224Z90 88 89 90

α β Y α

What are X, Y and Z?

X Y Z

A 228 α Th

B 228 β Ra

C 232 α Th

D 232 β Ra

20

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© UCLES 2015 9702/11/O/N/15

BLANK PAGE



*4235130509*


PHYSICS 9702/12


1 hour













2

© UCLES 2015 9702/12/O/N/15

Data



H m–1


F m–1

(0

4

1

επ

= 8.99 × 109 m F–1)










kg–2


3


Formulae


2

1at

v

2 = u

2 + 2as



r

Gm



Nm3

1 <c

2>


2x


v = ± ω )( 22

0xx −


Q

04 επ




1






2

1

0.693

t

4

© UCLES 2015 9702/12/O/N/15

1 Which list shows increasing lengths from beginning to end?

A 1 cm 1 nm 1 mm 1 µm

B 1 µm 1 mm 1 nm 1 cm

C 1 nm 1 µm 1 mm 1 cm

D 1 mm 1 cm 1 µm 1 nm 2 Which equation contains only scalar quantities?

A acceleration = mass

force

B power = time

work

C pressure = area

force

D velocity = time

ntdisplaceme

3 The time T taken for a satellite to orbit the Earth on a circular path is given by the equation

T

2 = M

kr 3

where r is the radius of the orbit, M is the mass of the Earth and k is a constant.

What are the SI base units of k ?

A kg–1 m–3

s2 B kg–1 m3

s2 C kg m–3 s2 D kg m3

s2 4 Which row gives reasonable estimates for the mass and the speed of an adult running?

mass / kg speed / m s–1

A 6 × 100 5 × 101

B 6 × 101 5 × 100

C 6 × 101 5 × 101

D 6 × 102 5 × 100

5


5 A student measures the time T for one complete oscillation of a pendulum of length l.

Her results are shown in the table.

l / m T / s

0.420 ± 0.001 1.3 ± 0.1

She uses the formula

T = 2πg

l

to calculate the acceleration of free fall g.

What is the best estimate of the percentage uncertainty in the value of g?

A 0.02% B 4% C 8% D 16% 6 The diagram shows two complete pulses on the screen of a cathode-ray oscilloscope. A grid of

1 cm squares covers the screen. The time-base setting is 1 µs cm–1.

1 cm

How long does each pulse last?

A 2 µs B 3 µs C 4 µs D 6 µs

6

© UCLES 2015 9702/12/O/N/15

7 A boy throws a ball vertically upwards. It rises to a maximum height, where it is momentarily at rest, and then falls back to his hands.

Which row gives the acceleration of the ball at various stages in its motion? (Take vertically upwards as positive. Ignore air resistance.)

rising at maximum

height falling

A –9.81 m s–2 0 +9.81 m s–2

B –9.81 m s–2 –9.81 m s–2 –9.81 m s–2

C +9.81 m s–2 +9.81 m s–2 +9.81 m s–2

D +9.81 m s–2 0 –9.81 m s–2

8 The curved line PQR is the velocity-time graph for a car starting from rest.

velocity

time / s0 50

Q

P S

R

What is the average acceleration of the car over the first 5 s?

A the area below the curve PQ

B the area of the triangle PQS

C the gradient of the straight line PQ

D the gradient of the tangent at Q

7


9 A ball is released from rest above a horizontal surface. It strikes the surface and bounces several times.

The velocity-time graph for the first two bounces is shown.

3.00

2.00

0

–2.00

0.30 0.50 0.70

velocity/ m s–1

time / s0

What is the maximum height of the ball after the first bounce?

A 0.20 m B 0.25 m C 0.45 m D 0.65 m 10 A bus takes a time of 25 s to reach a constant speed while travelling in a straight line. A graph of

speed v against time t is shown.

00 5 10 15 20 25

t / s

v

Which graph shows the variation with t of the resultant force F on the bus?

00 5 10 15 20 25

t / s

F

A

00 5 10 15 20 25

t / s

F

B

00 5 10 15 20 25

t / s

F

C

00 5 10 15 20 25

t / s

F

D

8

© UCLES 2015 9702/12/O/N/15

11 A single horizontal force F is applied to a block X which is in contact with a separate block Y as shown.

FX

Y

The blocks remain in contact as they accelerate along a horizontal frictionless surface. Air resistance is negligible. X has a greater mass than Y.

Which statement is correct?

A The acceleration of X is equal to force F divided by the mass of X.

B The force that X exerts on Y is equal to F.

C The force that X exerts on Y is less than F.

D The force that X exerts on Y is less than the force that Y exerts on X.

9


12 A mass of 0.20 kg is suspended from the lower end of a light spring. A second mass of 0.10 kg is suspended from the first mass by a thread. The arrangement is allowed to come into static equilibrium and then the thread is burned through.

0.20 kg

0.10 kg

spring

thread

At this instant, what is the upward acceleration of the 0.20 kg mass? (Assume g = 10 m s–2.)

A 5.0 m s–2 B 6.7 m s–2 C 10 m s–2 D 15 m s–2 13 An object of mass m travelling with speed v has a head-on collision with another object of mass

m travelling with speed v in the opposite direction. The two objects stick together after the collision.

What is the total loss of kinetic energy in the collision?

A 0 B 2

1 mv

2 C mv

2 D 2mv

2

14 Two identical spheres X and Y approach each other with the speeds shown and undergo a head-

on elastic collision.

X4 m s–1

Y2 m s–1

What are the velocities of the spheres after the collision?

D

B

A

C

4 m s–1

sphere X

2 m s–1

0 m s–1

2 m s–1

2 m s–1

sphere Y

4 m s–1

2 m s–1

4 m s–1

10

© UCLES 2015 9702/12/O/N/15

15 Which pair of forces acts only as a couple on the circular object?

F

F

A

2F

2F

F

B

F F

C

F

D

16 A car of mass 500 kg is at rest at point X on a slope, as shown.

The car’s brakes are released and the car rolls down the slope with its engine switched off. At point Y the car has moved through a vertical height of 30 m and has a speed of 11 m s–1.

X

Y

mass = 500 kgspeed = 0 m s–1

speed = 11 m s–130 m

What is the energy dissipated by frictional forces when the car moves from X to Y?

A 3.0 × 104 J B 1.2 × 105

J C 1.5 × 105 J D 1.8 × 105

J 17 In which situation is no work done?

A The air in a bicycle tyre is released because of a puncture.

B A ball is dropped and falls to the ground.

C A box moves at constant speed across a smooth horizontal surface.

D A crane lifts a steel girder at constant speed.

11


18 An electric railway locomotive has a maximum mechanical output power of 4.0 MW. Electrical power is delivered at 25 kV from overhead wires. The overall efficiency of the locomotive in converting electrical power to mechanical power is 80 %.

What is the current from the overhead wires when the locomotive is operating at its maximum power?

A 130 A B 160 A C 200 A D 250 A 19 The table summarises some descriptions of evaporation.

Which row of the table is correct?

involves a change in state

from liquid to vapour occurs at a fixed

temperature

involves a reduction in the average kinetic energy of the remaining atoms

A true true true

B true false true

C true false false

D false true false

20 The diagram shows the cross-section of an Olympic-size swimming pool filled with water. It is not

drawn to scale. The density of the water is 1000 kg m–3.

50 m

6.00 m

2.35 m 2.00 m

water

bottomof pool

XY

What is the difference in pressure between X and Y?

A 0.35 kPa B 3.4 kPa C 21.3 kPa D 58.9 kPa 21 A force acts on a wire to produce extension e. The same force then acts on a second wire of the

same material, but of half the diameter and three times the length of the first wire. Both wires obey Hooke’s law.

What is the extension of the second wire?

A 3e B 4e C 6e D 12e

12

© UCLES 2015 9702/12/O/N/15

22 Which statement about elastic and plastic deformation is correct?

A Elastic deformation and plastic deformation are proportional to the applied force.

B Elastic deformation and plastic deformation cause no change in volume.

C Elastic deformation causes heating of the material but plastic deformation does not.

D Elastic deformation is reversible but plastic deformation is not. 23 What is meant by the ultimate tensile stress of a ductile metal?

A It is the maximum stress at which the material deforms elastically.

B It is the maximum stress at which the material obeys Hooke’s law.

C It is the maximum stress that the material can support without breaking.

D It is the Young modulus multiplied by the maximum possible strain of a material. 24 A 0.80 m length of steel wire and a 1.4 m length of brass wire are joined together. The combined

wires are suspended from a fixed support and a force of 40 N is applied, as shown.

40 N

steel

brass

The Young modulus of steel is 2.0 × 1011 Pa.

The Young modulus of brass is 1.0 × 1011 Pa.

Each wire has a cross-sectional area of 2.4 × 10–6 m2.

The wires extend without reaching their elastic limits.

What is the total extension? Ignore the weights of the wires.

A 1.7 × 10–4 m B 3.0 × 10–4

m C 3.9 × 10–4 m D 9.0 × 10–4

m

13


25 Which of the following wave motions may be used to demonstrate the phenomenon of polarisation?

A a sound wave from a thunderclap

B a surface wave in a water ripple tank

C a stationary wave in an organ pipe

D a stationary wave on a stretched wire 26 The diagram shows the screen of a cathode-ray oscilloscope (c.r.o.) displaying a wave.

The time-base of the c.r.o. is set at 10 ms / div.

What is the frequency of the wave?

A 0.24 Hz B 4.2 Hz C 12 Hz D 24 Hz 27 P is a source emitting infra-red radiation and Q is a source emitting ultra-violet radiation. The

figures in the table are suggested values for the wavelengths emitted by P and Q.

Which row is correct?

wavelength

emitted by P / m wavelength

emitted by Q / m

A 5 × 10–5 5 × 10–8

B 5 × 10–5 5 × 10–10

C 5 × 10–7 5 × 10–8

D 5 × 10–7 5 × 10–10

14

© UCLES 2015 9702/12/O/N/15

28 The diagram shows a tuning fork above a tube of air of length 25 cm.

25 cm

A stationary wave is set up in the tube with the same frequency as the tuning fork. The lower end of the tube is sealed. This is the minimum length of tube with the lower end sealed that creates a stationary wave.

Which other lengths of tubes, sealed at their lower end, will also create a stationary wave?

A 37.5 cm and 50 cm

B 50 cm and 75 cm

C 75 cm and 100 cm

D 75 cm and 125 cm

15


29 White light consists of many wavelengths. The wavelength of red light R is approximately twice the wavelength of violet light V. When white light is incident normally on a diffraction grating, several spectra can be formed.

Which diagram shows the possible distributions of light in the first order and the second order spectra?

V

RV

R

2nd orderspectrum

1st orderspectrum

white white

A

V

VR

R

2nd orderspectrum

1st orderspectrum

white

B

RV

1st orderspectrum

R

VR

V

2nd orderspectrum

1st orderspectrum

white white

C

R

V

2nd orderspectrum

white

D

30 To produce a stationary wave, two waves must travel in opposite directions through the same

space.

Which statement about the properties of the two waves must also be true?

A The waves must have equal frequency, but a different speed and wavelength.

B The waves must have equal speed, but a different wavelength and frequency.

C The waves must have equal speed, frequency and wavelength.

D The waves must have equal wavelength, but a different speed and frequency.

16

© UCLES 2015 9702/12/O/N/15

31 A potential difference is applied between two metal plates that are not parallel.

Which diagram shows the electric field between the plates?

+ –

A

+ –

B

+ –

C

+ –

D

32 A particle situated between two parallel metal plates carries a charge of 8 × 10–19 C.

The potential difference (p.d.) between the plates is 2000 V. A force of 3.2 × 10–13 N due to the

electric field acts on the particle.

What is the distance between the plates?

A 5 mm B 8 mm C 5 cm D 8 cm 33 Which unit is equivalent to a coulomb (C)?

A A s B Ω s C V s D W s

17


34 The graph shows the I-V characteristic of an electrical component.

I

V000

What is the component?

A a filament lamp

B a metallic conductor at constant temperature

C a semiconductor diode

D a thermistor

35 A power supply of electromotive force (e.m.f.) 12 V and internal resistance 2 Ω is connected in

series with a load resistor. The resistance of the load resistor is varied from 0.5 Ω to 4 Ω.

Which graph shows how the power P dissipated in the load resistor varies with the resistance of the load resistor?

P

resistance of load / Ω0 1 2 3 4

resistance of load / Ω0

01 2 3 4

D

P


C

P

BA

P


0 0

0

18

© UCLES 2015 9702/12/O/N/15

36 The diagram shows an arrangement of resistors.

Y

X

10 Ω 10 Ω

10 Ω

10 Ω

What is the total electrical resistance between X and Y?

A less than 1 Ω

B between 1 Ω and 10 Ω

C between 10 Ω and 30 Ω

D 40 Ω 37 The electromotive force of a power supply is 120 V. It delivers a current of 1.2 A to a resistor of

resistance 80 Ω and a current of 0.40 A to another resistor, as shown.

e.m.f. of supply120 V

1.2 A

0.40 A

80 Ω

What is the internal resistance of the power supply?

A 15 Ω B 20 Ω C 60 Ω D 75 Ω

19

© UCLES 2015 9702/12/O/N/15

38 The diagram shows a four-terminal box connected to a battery and two ammeters.

A

A

1 3

2 4

The currents in the two meters are identical.

Which circuit, within the box, will give this result?

1 3

2 4

A

1 3

2 4

B

1 3

2 4

C

1 3

2 4

D

39 A material contains a radioactive isotope that disintegrates solely by the emission of α-particles at a rate of 100 s–1.

Which statement about this material is correct?

A The number of atoms in the material diminishes at a rate of 100 s–1.

B The number of neutrons in the material diminishes at a rate of 100 s–1.

C The number of nucleons in the material diminishes at a rate of 400 s–1.

D The number of protons in the material diminishes at a rate of 100 s–1.

40 A radioactive nucleus emits an α-particle or a β-particle, creating a product nucleus.

Which decay process could create the product nucleus stated?

radioactive nucleus decay product nucleus

A Ra226

88 α Rn

224

86

B U238

92 α Pu

242

94

C Ra228

88 β Fr

228

87

D Th231

90 β Pa

231

91

20



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This document consists of 21 printed pages and 3 blank pages.


*9866071575*


PHYSICS 9702/13


1 hour













2

© UCLES 2015 9702/13/O/N/15

Data



H m–1


F m–1

(0

4

1

επ

= 8.99 × 109 m F–1)










kg–2


3


Formulae


2

1at

v

2 = u

2 + 2as



r

Gm



Nm3

1 <c

2>


2x


v = ± ω )( 22

0xx −


Q

04 επ




1






2

1

0.693

t

4

© UCLES 2015 9702/13/O/N/15

1 What is the unit of the Young modulus when expressed in SI base units?

A kg m–1 s–2

B kg m3 s–2

C kg m–2

D kg m–1 s–1

2 The Reynolds number R is a constant used in the study of liquids flowing through pipes. R is a

pure number with no unit.

R = µ

ρvD

where ρ is the density of the liquid, v is the speed of the liquid and D is the diameter of the pipe through which the liquid flows.

What are the SI base units of µ?

A kg m s B kg m–1 s C kg m s–1 D kg m–1

s–1 3 When a force F moves its point of application through a displacement s in the direction of the

force, the work W done by the force is given by

W = F s.

How many vector quantities and scalar quantities does this equation contain?

A one scalar quantity and two vector quantities

B one vector quantity and two scalar quantities

C three scalar quantities

D three vector quantities 4 Measurements are subject to systematic error and random error.

Which measurements have high accuracy and low precision?

A high random error and high systematic error

B high random error and low systematic error

C low random error and high systematic error

D low random error and low systematic error

5


5 The density of the material of a coil of thin wire is to be found.

Which set of instruments could be used to do this most accurately?

A metre rule, protractor, spring balance

B micrometer, metre rule, top-pan balance

C stopwatch, newton-meter, vernier calipers

D tape measure, vernier calipers, lever balance

6 A cylindrical tube rolling down a slope of inclination θ moves a distance L in time T. The equation relating these quantities is

L

+

P

a2

3 = QT

2 sin θ

where a is the internal radius of the tube and P and Q are constants. Which row gives the correct units for P and for Q?

P Q

A m2 m2 s–2

B m2 m s–2

C m2 m3 s–2

D m3 m s–2

6

© UCLES 2015 9702/13/O/N/15

7 Variables x and y are related by the equation y = p – qx where p and q are constants.

Values of x and y are measured experimentally. The results contain a systematic error.

Which graph best represents these results?

A

p

00

y

x

B

p

00

y

x

C

p

00

y

x

D

p

00

y

x

7


8 A cheetah and an antelope are 100 m apart. The cheetah spots the antelope and runs towards it. The antelope reacts to the cheetah after one second and runs directly away from the cheetah. Both animals take 2 seconds to reach their top speeds. The graph shows how the speeds of the two animals vary with time.

0 5 10 15 20

35

30

25

20

15

10

5

0

speedm s–1

time / s

cheetah

antelope

How far apart are the animals, 17 seconds after the cheetah began running?

A 4 m B 11 m C 54 m D 89 m 9 A boy throws a stone with a horizontal velocity of 10 m s–1 from the top of a building. The height of

the building is 8.0 m. The stone travels along a curved path until it hits the ground, as shown in the diagram.

building

8.0 m

10 m s–1

ground

How long does it take the stone to reach the ground? (Air resistance can be neglected.)

A 0.61 s B 0.80 s C 1.3 s D 1.6 s

8

© UCLES 2015 9702/13/O/N/15

10 A football is released above a plane, sloping surface and bounces several times. The diagram shows its path between its bounces at X and at Y. Assume that there is no air resistance.

X

Y

Which graph correctly shows the variation with time t of the horizontal component of its velocity vh between X and Y?

vh

t 0 0

A vh

t 0 0

B

vh

t 0 0

C vh

t 0 0

D

11 A rocket of mass 30 000 kg sits on a launch pad on the Earth’s surface. The rocket motors

provide an upward force of 330 kN on the rocket.

What is the initial acceleration of the rocket?

A 0.12 m s–2

B 1.1 m s–2

C 1.2 m s–2

D 11 m s–2

9


12 Two equal masses X and Y are moving towards each other on a frictionless air track as shown. The masses make an elastic collision.

X Y

50 cm s–1 30 cm s–1air track

Which row gives possible velocities for the two masses after the collision?

velocity of X velocity of Y

A zero 20 cm s–1 to the right

B 10 cm s–1 to the right 10 cm s–1 to the right

C 20 cm s–1 to the left zero

D 30 cm s–1 to the left 50 cm s–1 to the right

13 Which statement is correct with reference to perfectly elastic collisions between two bodies?

A Neither total momentum nor total kinetic energy need be conserved but total energy must be conserved.

B Total momentum and total energy are conserved but total kinetic energy may be changed into some other form of energy.

C Total kinetic energy and total energy are both conserved but total momentum is conserved only if the two bodies have equal masses.

D Total momentum, total kinetic energy and total energy are all conserved. 14 Which statement best describes a couple?

A a pair of forces of equal magnitude acting in opposite directions which produce rotational motion but not translational motion

B a pair of forces of equal magnitude acting in opposite directions which produce translational motion but not rotational motion

C a pair of forces of equal magnitude acting in the same direction which produce rotational motion but not translational motion

D a pair of forces of equal magnitude acting in the same direction which produce translational motion but not rotational motion

10

© UCLES 2015 9702/13/O/N/15

15 A cross-shaped structure, freely pivoted at O, has arms of lengths 5.0 m, 4.0 m, 3.0 m and 2.0 m. It is acted on by forces of 2.0 N, 3.0 N, 4.0 N and an unknown force F. The structure is in rotational equilibrium.

2.0 m 4.0 m

2.0 N

4.0 N

3.0 N 3.0 m

5.0 m

30°

F

O

What is the magnitude of force F ?

A 0.40 N B 2.0 N C 2.6 N D 4.4 N

11


16 A trolley starts from rest at X. It rolls down to Y and eventually comes to rest at Z.

X

Y

Z

Which row is a possible summary of the energy changes during this process?

X to Y Y to Z

A p.e. → k.e. k.e. → p.e. key

B p.e. → k.e. k.e. → p.e. + heat p.e. = potential energy

C p.e. → k.e. + heat k.e. → p.e. k.e. = kinetic energy

D p.e. → k.e. + heat k.e. → p.e. + heat

17 An object of weight 15.0 N is pulled along a horizontal surface at a constant velocity of 2.00 m s–1.

The force pulling the object is 12.0 N at 30° to the horizontal, as shown.

15.0 N

2.00 m s–1

12.0 N

30°

What is the power used to move the object?

A 12.0 W B 20.8 W C 24.0 W D 30.0 W

12

© UCLES 2015 9702/13/O/N/15

18 Brownian motion can be demonstrated by illuminating smoke particles inside a closed, transparent container. When the particles are viewed using a microscope, bright specks of light are observed to move with constant, random motion.

What cannot be inferred from this observation?

A Air molecules are in constant motion.

B Air molecules are in random motion.

C Air pressure is due to air molecules colliding with the container.

D The mass of an air molecule is much less than the mass of a smoke particle. 19 A U-tube has one arm of area of cross-section A and the other of cross-section 4A. The tube

contains water of density 1000 kg m–3 and oil of density 850 kg m–3, as shown.

oil

30.0 cm

water

x

The column of oil on top of the water in the left-hand arm is of length 30.0 cm.

What is the difference in height x between the levels in the two arms of the tube?

A 4.5 cm B 6.2 cm C 23.8 cm D 25.5 cm

13


20 The Young modulus of a metal may be determined from the ratio strain

stress when the metal is

stretched elastically. This can be done by making measurements when loads are added to a wire.

Which measurements are needed to calculate the stress and strain of the wire in such an experiment?

stress strain

A

wire diameter

initial and final positions of load

wire’s original length

mass added

B

wire diameter

mass added



C



wire diameter

mass added

D


mass added

wire diameter


21 A copper wire of length 3.6 m and diameter 1.22 mm is stretched elastically by a force of 37 N.

The Young modulus of copper is 1.17 × 1011 Pa.

Which extension is caused by this force?

A 0.24 mm B 0.76 mm C 0.97 mm D 3.1 mm 22 When all the other features of a wave are constant, which relationship is correct?

A Amplitude is directly proportional to velocity.

B Intensity is directly proportional to amplitude.

C Velocity is directly proportional to wavelength.

D Wavelength is directly proportional to frequency.

14

© UCLES 2015 9702/13/O/N/15

23 A vibrating rod makes a water wave in a ripple tank. The graph shows the displacement of the wave at one instant as it travels away from the rod. The wave speed is 2.0 cm s–1.

4

2

0

–2

–4

0.40 0.8 1.2

displacement/ mm

distance / cm

What is the frequency of the wave?

A 0.8 Hz B 1.6 Hz C 2.5 Hz D 5.0 Hz 24 Polarisation is a phenomenon associated with a certain type of wave.

Which condition must be fulfilled if a wave is to be polarised?

A It must be a light wave.

B It must be a longitudinal wave.

C It must be a radio wave.

D It must be a transverse wave. 25 Monochromatic light passes through two narrow slits and produces an interference pattern on a

screen some distance away. The interference fringes are very close together.

Which change would increase the distance between the fringes?

A Increase the brightness of the light source.

B Increase the distance between the slits and the screen.

C Increase the distance between the two slits.

D Increase the frequency of the light used. 26 The following statements describe the diffraction of waves passing through a narrow slit.

Which statement is not correct?

A Both transverse and longitudinal waves can be diffracted.

B Diffraction can only be seen with light when the light is monochromatic.

C Red light diffracts through a greater angle than blue light.

D The angle of diffraction increases when the width of the slit decreases.

15


27 Monochromatic light is directed onto a pair of slits. Interference fringes that are 2.0 mm apart are observed on a distant screen.

The frequency of the light used is then doubled and the slit separation is halved.

How far apart are the new interference fringes?

A 0.50 mm B 2.0 mm C 4.0 mm D 8.0 mm

28 A diffraction grating has N lines per unit length and is placed at 90° to monochromatic light of

wavelength λ.

What is the expression for θ, the angle to the normal to the grating at which the third order diffraction peak is observed?

A sin θ = λN 3

1 B sin θ =

3

λN C sin θ = 3N λ D sin θ =

N

λ3

29 Two parallel plates R and S are 2 mm apart in a vacuum. An electron with charge –1.6 × 10–19 C

moves along a straight line in the electric field between the plates. The graph shows how the potential energy of the electron varies with its distance from plate R.

00

+4.8 × 10–19

1 2

potentialenergy / J

distance / mm

Which deduction is not correct?

A The electric field between R and S is uniform.

B The electric field strength is 3000 N C–1.

C The force on the electron is constant.

D The magnitude of the potential difference between R and S is 3 V.

16

© UCLES 2015 9702/13/O/N/15

30 Two parallel, conducting plates with air between them are placed close to one another. The top plate is given a negative charge and the bottom one is earthed.

Which diagram best represents the distribution of charges and the field between the plates?

A B

C D

+ + + + + + +

_ _ _ _ _ _ _

_ _ _ _ _ _ _

+ + + + + + +

_ _ _ _ _ _ _

_ _ _ _ _ _ _

31 In terms of energy transfer W and charge q, what are the definitions of potential difference (p.d.)

and electromotive force (e.m.f.)?

p.d. e.m.f.

A qW

qW

B qW

Wq

C Wq qW

D Wq Wq

17


32 A cell of electromotive force E and internal resistance r is connected to an external resistor, as shown.

VI

rE

The current in the circuit is I and the potential difference (p.d.) across the external resistor is V.

In the equation (E – V ) = Ir , what does the term (E – V ) represent?

A electrical energy per unit charge lost in the cell

B electrical energy per unit charge lost in the complete circuit

C electrical energy per unit charge lost in the connecting wire

D electrical energy per unit charge lost in the external resistor 33 Tensile strain may be measured by the change in electrical resistance of a device called a strain

gauge. A strain gauge consists of folded fine metal wire mounted on a flexible insulating backing sheet. The strain gauge is firmly attached to the specimen.

specimen

strain gauge

When the strain in the specimen is increased, what happens to the resistance of the wire?

A It decreases, because the length decreases and the cross-sectional area increases.

B It decreases, because the length increases and the cross-sectional area decreases.

C It increases, because the length decreases and the cross-sectional area increases.

D It increases, because the length increases and the cross-sectional area decreases.

18

© UCLES 2015 9702/13/O/N/15

34 In the circuit shown, lamp P is rated 250 V, 50 W and lamp Q is rated 250 V, 200 W. The two lamps are connected in series to a 250 V power supply.

P Q

250 V

Assume that the resistance of each lamp remains constant.

Which statement most accurately describes what happens when the switch is closed?

A Lamp P emits four times as much power as lamp Q.

B Lamp P emits twice as much power as lamp Q.

C Lamp Q emits four times as much power as lamp P.

D Lamp Q emits twice as much power as lamp P.

19


35 The cooling system in many houses is controlled by three electrical switches. These are:

• a thermostat switch that closes when the temperature rises to a given value,

• a clock switch that closes at times when cooling may be required,

• an override switch that closes to turn on the system when exceptional temperature rises occur.

Which diagram shows the switches correctly connected between the power supply and the cooling system?

clockthermostat

overridepower supplyA cooling system

overridethermostat

clockpower supplyD cooling system

overridethermostat clockpower supplyC cooling system

thermostat

override

clock

power supplyB cooling system

20

© UCLES 2015 9702/13/O/N/15

36 A 110 V supply of negligible internal resistance is connected to a heater through a fuse and a switch.

switchfuse

heater

C1

C2

110 VS+

S–

Terminals S+ and S– are the positive and negative terminals of the supply. Points C1 and C2 at either side of the heater are accessible for fault-finding.

A voltmeter is connected between S– and C1.

With the circuit working correctly, the voltmeter reading is noted with the switch closed.

A fault occurs and the voltmeter is again connected between S– and C1 with the switch closed.

Which fault would result in the same two voltmeter readings?

A a break in the wire of the heater

B a broken switch that cannot close correctly

C a melted fuse

D a short circuit in the heater

37 A network of resistors, each of resistance 1 Ω, is connected as shown.

V

1 Ω 1 Ω 1 Ω

1 Ω1 Ω

1 A

1 Ω

The current passing through the end resistor is 1 A.

What is the potential difference (p.d.) V across the input terminals?

A 2 V B 5 V C 8 V D 13 V

21

© UCLES 2015 9702/13/O/N/15

38 Two α-particles with equal energies are fired towards the nucleus of a gold atom.

Which diagram best represents their paths?

A

gold nucleus

B

gold nucleus

C

gold nucleus

D

gold nucleus

39 When a nucleus emits an α-particle, how do the proton number and the nucleon number of the original nucleus change?

proton number nucleon number

A –4 –2

B –2 –2

C –2 –4

D +1 no change

40 A simple theory of α-particle scattering by a thin metal foil uses the four assumptions given below.

Which assumption is exact and is not an approximation?

A Each α-particle interacts with just one nucleus.

B The α-particles lose no kinetic energy when they are deflected.

C The metal nuclei do not recoil.

D Total momentum is conserved.

22

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DC (LK/SW) 97490/3© UCLES 2015 [Turn over

Cambridge International ExaminationsCambridge International Advanced Subsidiary and Advanced Level

*9470674854*

PHYSICS 9702/21

Paper 2 AS Structured Questions October/November 2015

1 hour

Candidates answer on the Question Paper.

No Additional Materials are required.


Write your Centre number, candidate number and name on all the work you hand in.Write in dark blue or black pen.You may use an HB pencil for any diagrams or graphs.Do not use staples, paper clips, glue or correction fluid.DO NOT WRITE IN ANY BARCODES.

Answer all questions.

Electronic calculators may be used.You may lose marks if you do not show your working or if you do not use appropriate units.

At the end of the examination, fasten all your work securely together.The number of marks is given in brackets [ ] at the end of each question or part question.

2

9702/21/O/N/15© UCLES 2015

Data


permeability of free space, μ0 = 4π × 10–7 H m–1

permittivity of free space, ε0 = 8.85 × 10–12 F m–1

(

14πε0

= 8.99 × 109 m F–1)









gravitational constant, G = 6.67 × 10–11 N m2 kg–2


3

9702/21/O/N/15© UCLES 2015 [Turn over

Formulae

uniformly accelerated motion, s = ut + 12at 2

v2 = u2 + 2as

work done on/by a gas, W = pV

gravitational potential, φ = – Gmr

hydrostatic pressure, p = ρgh

pressure of an ideal gas, p = 13

NmV

<c 2>

simple harmonic motion, a = – ω 2x


v = ± ω (x02 – x 2)

electric potential, V = Q4πε0r

capacitors in series, 1/C = 1/C1 + 1/C2 + . . .


energy of charged capacitor, W = 12 QV


resistors in parallel, 1/R = 1/R1 + 1/R2 + . . .


radioactive decay, x = x0 exp(– λt)

decay constant, λ = 0.693t 1

2

4

9702/21/O/N/15© UCLES 2015

Answer all the questions in the spaces provided.

1 (a) State two SΙ base quantities other than mass, length and time.

1. ...............................................................................................................................................

2. ...............................................................................................................................................[2]

(b) A beam is clamped at one end and an object X is attached to the other end of the beam, as shown in Fig. 1.1.

l

clamp beam object X

oscillationof X

Fig. 1.1

The object X is made to oscillate vertically.

The time period T of the oscillations is given by

T = K Ml 3

E

where M is the mass of X,l is the length between the clamp and X, E is the Young modulus of the material of the beam

and K is a constant.

(i) 1. Show that the SΙ base units of the Young modulus are kg m–1 s–2.

[1]

5


2. Determine the SΙ base units of K.

SΙ base units of K .......................................................... [2]

(ii) Data in SΙ units for the oscillations of X are shown in Fig. 1.2.

quantity value uncertainty

T 0.45 ± 2.0%

l 0.892 ± 0.2%

M 0.2068 ± 0.1%

K 1.48 × 105 ± 1.5%

Fig. 1.2

Calculate E and its actual uncertainty.

E = ..................................... ± ..................................... kg m–1 s–2 [4]

6

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7


2 The signal from a microwave detector is recorded on a cathode-ray oscilloscope (c.r.o.), as shown in Fig. 2.1.

1 cm

1 cm

Fig. 2.1

The time-base setting on the c.r.o. is 50 ps cm–1.

(a) Using Fig. 2.1, determine the wavelength of the microwaves.

wavelength = ........................................................ m [4]

(b) The signal from a radio wave detector is recorded on the same c.r.o. The wavelength of the radio waves is 1.5 × 103 m.

Determine the time-base setting required to display the same number of oscillations on the c.r.o. as shown in Fig. 2.1.

time-base setting = ....................................... unit........................ [2]

8

9702/21/O/N/15© UCLES 2015

3 (a) An object is moved from point P to point R either by a direct path or by the path P to Q to R, as shown in Fig. 3.1.

horizontal

vertical

R

QP

object

Fig. 3.1

P and Q are on the same horizontal level. R is vertically above Q.

Explain whether the work done moving the object against the gravitational field is the same or different along paths PR and PQR.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) A ball is thrown with an initial velocity V at an angle θ to the horizontal, as shown in Fig. 3.2.

path of ball

horizontal

V

Fig. 3.2 (not to scale)

The variation with time t of the height h of the ball is shown in Fig. 3.3.

00

2.0

4.0

6.0

8.0

10.0h / m

t / s

12.0

1.00 2.00 3.00

Fig. 3.3

Air resistance is negligible.

9


(i) Use the time to reach maximum height to determine the vertical component Vv of the velocity of the ball for time t = 0.

Vv = ........................................................ m s–1 [2]

(ii) The horizontal displacement of the ball at t = 3.00 s is 25.5 m. On Fig. 3.4, draw the variation with t of the horizontal displacement x of the ball.

00

10

20

x / m

t / s

30

1.00 2.00 3.00

Fig. 3.4[1]

(iii) For the ball at maximum height, calculate the ratio

potential energy of the ballkinetic energy of the ball

.

ratio = .......................................................... [3]

(iv) In practice, air resistance is not negligible. State and explain the effect of air resistance on the time taken for the ball to reach maximum height.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

10

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4 Fig. 4.1 shows a metal cylinder of height 4.5 cm and base area 24 cm2.

metal cylinder4.5 cm

base area 24 cm2

Fig. 4.1

The density of the metal is 7900 kg m–3.

(a) Show that the mass of the cylinder is 0.85 kg.

[2] (b) The cylinder is placed on a plank, as shown in Fig. 4.2.

horizontal40°

cylinder

plank

Fig. 4.2

The plank is at an angle of 40° to the horizontal.

11


Calculate the pressure on the plank due to the cylinder.

pressure = .................................................... Pa [3]

(c) The cylinder then slides down the plank with a constant acceleration of 3.8 m s–2. A constant frictional force f acts on the cylinder.

Calculate the frictional force f.

f = ...................................................... N [3]

12

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5 (a) A progressive wave transfers energy. A stationary wave does not transfer energy. State two other differences between progressive waves and stationary waves.

1. ...............................................................................................................................................

...................................................................................................................................................

2. ...............................................................................................................................................

...................................................................................................................................................[2]

(b) A stationary wave is formed on a stretched string between two fixed points A and B. The variation of the displacement y of particles of the string with distance x along the string

for the wave at time t = 0 is shown on Fig. 5.1.

–10

–5

0

5

10

y / mm

1.0 2.00x / m

A B

position ofparticles at t = 0

Fig. 5.1

The wave has a period of 20 ms and a wavelength of 1.2 m. The maximum amplitude of the particles of the string is 5.0 mm.

(i) On Fig. 5.1, draw a line to represent the position of the string at t = 5.0 ms. [2]

(ii) State the phase difference between the particles of the string at x = 0.40 m and at x = 0.80 m.

phase difference = ......................... unit .................... [1]

(iii) State and explain the change in the kinetic energy of a particle at an antinode between t = 0 and t = 5.0 ms. A numerical value is not required.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

13


6 (a) Define electromotive force (e.m.f.) for a battery.

...................................................................................................................................................

.............................................................................................................................................. [1]

(b) A battery of e.m.f. 6.0 V and internal resistance 0.50 Ω is connected in series with two resistors X and Y, as shown in Fig. 6.1.

6.0 V 0.50

12 4.0

YX

Fig. 6.1

The resistance of X is 4.0 Ω and the resistance of Y is 12 Ω.

Calculate

(i) the current in the circuit,

current = ....................................................... A [2]

(ii) the terminal potential difference (p.d.) across the battery.

p.d. = ....................................................... V [1]

14

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(c) A resistor Z is now connected in parallel with resistor Y in the circuit in (b). The new arrangement is shown in Fig. 6.2.

6.0 V 0.50

12 4.0

Y

Z

X

Fig. 6.2

Resistor Y is made from a wire of length l and diameter d. Resistor Z is a wire made from the same material as Y. The length of the wire for Z is l / 2 and the diameter is d / 2.

(i) Calculate the resistance R of the combination of resistors Y and Z.

R = ....................................................... Ω [3]

(ii) State and explain the effect on the terminal p.d. across the battery.

A numerical value is not required.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

15


(d) For the circuits given in (b) and (c), show that the ratio

power developed in the external circuit in Fig. 6.1power developed in the external circuit in Fig. 6.2

is approximately 0.8.

[3]

7 Two parallel, vertical metal plates in a vacuum are connected to a power supply and a switch, as shown in Fig. 7.1.

metal

radioactivesource

metal

path of -particles

+

powersupply

–

Fig. 7.1

A radioactive source emitting α-particles is placed below the plates. The path of the α-particles is shown on Fig. 7.1. The switch is closed producing a potential difference (p.d.) across the plates. This gives rise to a uniform electric field between the plates.

The separation of the plates is 12 mm.

(a) (i) On Fig. 7.1, draw the path of the α-particles. [1]

(ii) Explain why the metal plates are placed in a vacuum.

...........................................................................................................................................

...................................................................................................................................... [1]

16

9702/21/O/N/15© UCLES 2015

Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.

To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cie.org.uk after the live examination series.


(iii) Calculate the p.d. required to produce an electric field of 140 MV m–1.

p.d. = ................................................... MV [2]

(b) The α-particle source is replaced by a β-particle source. By reference to the properties of α-radiation and β-radiation, suggest three possible differences in the deflection observed with β-particles.

1. ...............................................................................................................................................

...................................................................................................................................................

2. ...............................................................................................................................................

...................................................................................................................................................

3. ...............................................................................................................................................

................................................................................................................................................... [3]

(c) Complete Fig. 7.2 to show the changes in the proton number Z and the nucleon number A of different radioactive nuclei when either an α-particle or a β-particle is emitted.

emitted particle change in Z change in A

α-particle

β-particle

Fig. 7.2[1]

This document consists of 16 printed pages.

DC (LEG/CGW) 96939/2© UCLES 2015 [Turn over


*5802267223*

PHYSICS 9702/22


1 hour








2

9702/22/O/N/15© UCLES 2015

Data




(

14πε0

= 8.99 × 109 m F–1)











3


Formulae


v2 = u2 + 2as





NmV

<c 2>



v = ± ω (x02 – x 2)








radioactive decay, x = x0 exp(– λt)


2

4

9702/22/O/N/15© UCLES 2015


1 (a) The frequency of an X-ray wave is 4.6 × 1020 Hz.

Calculate the wavelength in pm.

wavelength = .................................................... pm [3]

(b) The distance from Earth to a star is 8.5 × 1016 m. Calculate the time for light to travel from the star to Earth in Gs.

time = .................................................... Gs [2]

(c) The following list contains scalar and vector quantities.

Underline all the scalar quantities.

acceleration force mass power temperature weight [1]

(d) A boat is travelling in a flowing river. Fig. 1.1 shows the velocity vectors for the boat and the river water.

boat velocity 14.0 m s–1

water velocity 8.0 m s–1

60° east

Fig. 1.1

The velocity of the boat in still water is 14.0 m s–1 to the east. The velocity of the water is 8.0 m s–1 from 60° north of east.

5


(i) On Fig. 1.1, draw an arrow to show the direction of the resultant velocity of the boat. [1]

(ii) Determine the magnitude of the resultant velocity of the boat.

magnitude of velocity = ................................................ m s–1 [2]

6

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2 Fig. 2.1 shows an object M on a slope.

Q

P

R

M

3.6 m s–1

Fig. 2.1

M moves up the slope, comes to rest at point Q and then moves back down the slope to point R. M has a constant acceleration of 3.0 m s–2 down the slope at all times. At time t = 0, M is at point P and has a velocity of 3.6 m s–1 up the slope. The total distance from P to Q and then to R is 6.0 m.

(a) Calculate, for the motion of M from P to Q, (i) the time taken,

time = ....................................................... s [2]

(ii) the distance travelled.

distance = ...................................................... m [1]

(b) Show that the speed of M at R is 4.8 m s–1.

[2]

7


(c) On Fig. 2.2, draw the variation with time t of the velocity v of M for the motion P to Q to R.

–2.0

2.0v / m s–1

4.0

6.0

0

–4.0

–6.0

0.50 1.0 1.5 2.0 2.5 3.0 3.5t / s

Fig. 2.2 [3]

(d) The mass of M is 450 g.

Calculate the difference in the kinetic energy of M at P and at R.

difference in kinetic energy = ....................................................... J [2]

8

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3 A trolley T moves at speed 1.2 m s–1 along a horizontal frictionless surface. The trolley collides with a stationary block on the end of a fixed spring, as shown in Fig. 3.1.

T

blockfixed endof spring

horizontal frictionless surface

1.2 m s–1

Fig. 3.1

The mass of T is 250 g. T compresses the spring by 5.4 cm as it comes to rest. The relationship between the force F applied to the block and the compression x of the spring is

shown in Fig. 3.2.

6.0

5.0

4.0

3.0

2.00 4.0F / N

x / cm

6.0

2.0

1.0

0

Fig. 3.2

(a) Use Fig. 3.2 to determine

(i) the spring constant of the spring,

spring constant = ................................................ N m–1 [2]

9


(ii) the work done by T compressing the spring by 5.4 cm.

work done = ....................................................... J [2]

(b) The spring then expands and causes T to move in a direction opposite to its initial direction. At the time that T loses contact with the block, it is moving at a speed of 0.75 m s–1.

From the time that T is in contact with the block,

(i) describe the energy changes,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) determine the change in momentum of T.

change in momentum = .................................................... N s [2]

10

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4 (a) Define moment of a force.

...................................................................................................................................................

...............................................................................................................................................[1]

(b) An arrangement for lifting heavy loads is shown in Fig. 4.1.

wallbeam

load

4000 N500 NA

B

TC

60°

30°

2.8 m2.8 m

Fig. 4.1

A uniform metal beam AB is pivoted on a vertical wall at A. The beam is supported by a wire joining end B to the wall at C. The beam makes an angle of 30° with the wall and the wire makes an angle of 60° with the wall.

The beam has length 2.8 m and weight of 500 N. A load of 4000 N is supported from B. The tension in the wire is T. The beam is in equilibrium.

(i) By taking moments about A, show that T is 2.1 kN.

[2]

(ii) Calculate the vertical component Tv of the tension T.

Tv = ...................................................... N [1]

(iii) State and explain why Tv does not equal the sum of the load and the weight of the beam although the beam is in equilibrium.

...........................................................................................................................................

.......................................................................................................................................[2]

11


5 A 240 V power supply S with negligible internal resistance is connected to four resistors, as shown in Fig. 5.1.

240 V0.40 A

A

S

I1

I2 B

950 550

R350

Fig. 5.1

Two resistors of resistance 550 Ω and 950 Ω are connected in series across S. Two resistors of resistance 350 Ω and R are also connected in series across S.

The current supplied by S is 0.40 A. Currents I1 and I2 in the circuit are shown in Fig. 5.1.

(a) Calculate

(i) current I1,

I1 = ...................................................... A [2]

(ii) resistance R,

R = .......................................................Ω [2]

(iii) the ratio

power transformed in resistor of resistance 350 Ωpower transformed in resistor of resistance 550 Ω

.

ratio = .......................................................... [2]

12

9702/22/O/N/15© UCLES 2015

(b) Two points are labelled A and B, as shown in Fig. 5.1.

(i) Calculate the potential difference VAB between A and B.

VAB = ...................................................... V [2]

(ii) The resistance R is increased.

State and explain the effect on VAB.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

13


6 A 12 V battery with internal resistance 0.50 Ω is connected to two identical filament lamps L1 and L2 as shown in Fig. 6.1.

S1

S2 L2

L1

12 V

0.50

Fig. 6.1

The lamps are connected to the battery via switches S1 and S2. The power rating of each lamp is 48 W for a potential difference of 12 V.

(a) S1 is closed and S2 open.

State and explain whether the power transformed in L1 is 48 W.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) S2 is now also closed.

(i) State and explain the effect on the current in L1.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

(ii) State and explain the effect on the resistance of L1.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

14

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7 An arrangement that is used to demonstrate interference with waves on the surface of water is shown in Fig. 7.1.

A

B

watermotor

wooden bardipper

to d.c. powersupply

dipper

D2

D1

Fig. 7.1 (view from above)

(a) Two dippers D1 and D2 are connected to a motor and a d.c. power supply. Initially only D1 vibrates on the water surface to produce waves.

The variation with distance x from D1 of the displacement y of the water at one instant of time is shown in Fig. 7.2.

–2.0

2.0y / mm

4.0

0

–4.0

100 20 30 40 50x / mm

Fig. 7.2

Using Fig. 7.2, determine

(i) the amplitude of the wave,

amplitude = ................................................... mm [1]

(ii) the wavelength of the wave.

wavelength = ................................................... mm [1]

15


(b) The two dippers D1 and D2 are made to vibrate and waves are produced by both dippers on the water surface.

(i) State and explain whether these waves are stationary or progressive.

...........................................................................................................................................

.......................................................................................................................................[1]

(ii) Explain why D1 and D2 are connected to the same motor.

...........................................................................................................................................

.......................................................................................................................................[1]

(c) The points A and B on Fig. 7.1 are at the distances from D1 and D2 shown in Fig. 7.3.

D1A D2A D1B D2B

5.0 cm 7.0 cm 5.0 cm 6.0 cm

Fig. 7.3

State and explain the variation with time of the displacement of the water on the surface at

(i) A,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) B.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

16

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8 (a) The results of the α-particle scattering experiment gave evidence for the structure of the atom.

State two results and the associated conclusions.

result 1: .....................................................................................................................................

...................................................................................................................................................

conclusion 1: .............................................................................................................................

................................................................................................................................................... result 2: .....................................................................................................................................

...................................................................................................................................................

conclusion 2: .............................................................................................................................

................................................................................................................................................... [4]

(b) In a model of a copper atom of the isotope 6329 Cu, the atom and its nucleus are assumed to be

spherical.

The diameter of the nucleus is 2.8 × 10–14 m. The diameter of the atom is 2.3 × 10–10 m.

Calculate the ratio

density of the nucleusdensity of the atom

.

ratio = ...........................................................[3]


DC (NH/CGW) 96937/2© UCLES 2015 [Turn over

*4861915021*

PHYSICS 9702/23


1 hour









2

9702/23/O/N/15© UCLES 2015

Data




(

14πε0

= 8.99 × 109 m F–1)











3


Formulae

uniformly accelerated motion, s = ut + at 2

v2 = u2 + 2as

work done on/by a gas, W = pΔV

gravitational potential, φ = – Gm

r


pressure of an ideal gas, p = NmV

<c2>



v = ± ω (x02 – x 2)




energy of charged capacitor, W = QV



alternating current/voltage, x = x0 sin ω t

radioactive decay, x = x0 exp(–λt )

decay constant, λ = 0.693

t

4

9702/23/O/N/15© UCLES 2015


1 (a) The intensity of a progressive wave is defined as the average power transmitted through a surface per unit area.

Show that the SI base units of intensity are kg s−3.

[2]

(b) (i) The intensity I of a sound wave is related to the amplitude x0 of the wave by

I = Kρcf 2x02

where ρ is the density of the medium through which the sound is passing, c is the speed of the sound wave, f is the frequency of the sound wave and K is a constant.

Show that K has no units.

[2]

5


(ii) Calculate the intensity, in pW m−2, of a sound wave where

K = 20, ρ = 1.2 in SI base units, c = 330 in SI base units, f = 260 in SI base units and x0 = 0.24 nm.

intensity = ..............................................pW m−2 [3]

6

9702/23/O/N/15© UCLES 2015

2 A signal generator is connected to two loudspeakers L1 and L2, as shown in Fig. 2.1.

signalgenerator

L1

C

B

AM

c.r.o.

L2

Fig. 2.1

A microphone M, connected to the Y-plates of a cathode-ray oscilloscope (c.r.o.), detects the intensity of sound along the line ABC.

The distances L1A and L2A are equal. The time-base of the c.r.o. is switched off.

The traces on the c.r.o. when M is at A, then at B and then at C are shown on Fig. 2.2, Fig. 2.3 and Fig. 2.4 respectively.

1.0 cm

M at A M at B M at C

Fig. 2.2 Fig. 2.3 Fig. 2.4

For these traces, 1.0 cm represents 5.0 mV on the vertical scale.

(a) (i) Explain why coherent waves are produced by the loudspeakers.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

7


(ii) Use the principle of superposition to explain the traces shown with M at

1. A,

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

2. B,

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

3. C.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

(b) The sound emitted from L1 and L2 has frequency 500 Hz. The time-base on the c.r.o. is switched on.

The microphone M is placed at A.

On Fig. 2.5, draw the trace seen on the c.r.o.

On the vertical scale, 1.0 cm represents 5.0 mV. On the horizontal scale, 1.0 cm represents 0.10 ms.

1.0 cm

1.0 cm

Fig. 2.5 [3]

8

9702/23/O/N/15© UCLES 2015

3 A steel ball falls from a platform on a tower to the ground below, as shown in Fig. 3.1.

192 mpath ofballtower

platform ball

ground

Fig. 3.1

The ball falls from rest through a vertical distance of 192 m. The mass of the ball is 270 g.

(a) Assume air resistance is negligible.

(i) Calculate

1. the time taken for the ball to fall to the ground,

time taken = ........................................................s [2]

2. the maximum kinetic energy of the ball.

maximum kinetic energy = ........................................................J [2]

(ii) State and explain the variation of the velocity of the ball with time as the ball falls to the ground.

...........................................................................................................................................

.......................................................................................................................................[1]

(iii) Show that the velocity of the ball on reaching the ground is approximately 60 m s–1.

[1]

9


(b) In practice, air resistance is not negligible. The variation of the air resistance R with the velocity v of the ball is shown in Fig. 3.2.

0 20

4.0

3.0

2.0

0

1.0

40 60 80v / m s–1

R / N

100

Fig. 3.2

(i) Use Fig. 3.2 to state and explain qualitatively the variation of the acceleration of the ball with the distance fallen by the ball.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) The speed of the ball reaches 40 m s–1. Calculate its acceleration at this speed.

acceleration = ................................................. m s–2 [2]

(iii) Use information from (a)(iii) and Fig. 3.2 to state and explain whether the ball reaches terminal velocity.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

10

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4 A block is pulled on a horizontal surface by a force P as shown in Fig. 4.1.

block

60°

vertical

horizontal

P = 35 N

weight = 180 N

Fig. 4.1

The weight of the block is 180 N. The force P is 35 N at 60° to the vertical. The block moves a distance of 20 m at constant velocity.

(a) Calculate

(i) the vertical force that the surface applies to the block (normal reaction force),

force = ....................................................... N [2]

(ii) the work done by force P.

work done = ........................................................J [2]

11


(b) (i) Explain why the block continues to move at constant velocity although work is done on the block by force P.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

(ii) Explain, in terms of the forces acting, why the block remains in equilibrium.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

12

9702/23/O/N/15© UCLES 2015

5 (a) The I-V characteristic of a semiconductor diode is shown in Fig. 5.1.

0 0.20

12.0

8.0

0

4.0

0.40 0.60 0.80V / V

I / mA

14.0

10.0

6.0

2.0

Fig. 5.1

(i) Use Fig. 5.1 to explain the variation of the resistance of the diode as V increases from zero to 0.8 V.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) Use Fig. 5.1 to determine the resistance of the diode for a current of 4.4 mA.

resistance = .......................................................Ω [2]

13


(b) A cell of e.m.f. 1.2 V and negligible internal resistance is connected in series to a semiconductor diode and a resistor R1, as shown in Fig. 5.2.

R1

R2

7.6 mA

1.2 V

375

Fig. 5.2

A resistor R2 of resistance 375 Ω is connected across the cell. The diode has the characteristic shown in Fig. 5.1. The current supplied by the cell is 7.6 mA.

Calculate

(i) the current in R2,

current = ....................................................... A [1]

(ii) the resistance of R1,

resistance = .......................................................Ω [2]

(iii) the ratio

power dissipated in the diodepower dissipated in R2

.

ratio = ...........................................................[2]

14

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6 An arrangement for producing stationary waves in air in a tube that is closed at one end is shown in Fig. 6.1.

signalgenerator

air

loudspeaker

Ltube of

adjustablelength

Fig. 6.1

A loudspeaker produces sound waves of wavelength 0.680 m in the tube. For some values of the length L of the tube, stationary waves are formed.

(a) Explain how stationary waves are formed in the tube.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) The length L is adjusted between 0.200 m and 1.00 m.

(i) Calculate two values of L for which stationary waves are formed.

L = .................................. m and L = .............................. m [2]

(ii) On Fig. 6.2, label the positions of the antinodes with an A and the nodes with an N for the least value of L for which a stationary wave is formed.

Fig. 6.2 [1]

15


7 A steel wire of cross-sectional area 15 mm2 has an ultimate tensile stress of 4.5 × 108 N m–2.

(a) Calculate the maximum tension that can be applied to the wire.

tension = ....................................................... N [2]

(b) The steel of the wire has density 7800 kg m–3. The wire is hung vertically.

Calculate the maximum length of the steel wire that could be hung vertically before the wire breaks under its own weight.

length = ...................................................... m [3]

Please turn over forQuestion 8.

16

9702/23/O/N/15© UCLES 2015




8 (a) State the quantities, other than momentum, that are conserved in a nuclear reaction.

...................................................................................................................................................

...............................................................................................................................................[2]

(b) A stationary nucleus of uranium-238 decays to a nucleus of thorium-234 by emitting an α-particle. The kinetic energy of the α-particle is 6.69 × 10–13 J.

(i) Show that the kinetic energy Ek of a mass m is related to its momentum p by the equation

Ek = p2

2m .

[1]

(ii) Use the conservation of momentum to determine the kinetic energy, in keV, of the thorium nucleus.

kinetic energy = ................................................... keV [3]


DC (LK/FD) 99940/3© UCLES 2015 [Turn over


*1378165508*

PHYSICS 9702/31

Paper 3 Advanced Practical Skills 1 October/November 2015

2 hours


Additional Materials: As listed in the Confidential Instructions.



Answer both questions.You will be allowed to work with the apparatus for a maximum of one hour for each question.You are expected to record all your observations as soon as these observations are made, and to plan the presentation of the records so that it is not necessary to make a fair copy of them.You are reminded of the need for good English and clear presentation in your answers.


Additional answer paper and graph paper should be used only if it becomes necessary to do so.


For Examiner’s Use

1

2

Total

2

9702/31/O/N/15© UCLES 2015

You may not need to use all of the materials provided.

1 In this experiment, you will investigate the effect of air resistance on the motion of a circular card.

(a) (i) Use the compasses to draw a circle of approximate diameter 20 cm on the card.

(ii) Use the scissors to cut out the circle.

(iii) Make a hole in the centre of the circle with the compasses. The hole should be big enough for the hook of the mass hanger to pass through.

(iv) Measure and record the diameter d of the card as shown in Fig. 1.1.

Fig. 1.1

d = .................................................. [1]

3


(b) (i) Set up the apparatus as shown in Fig. 1.2. The rule should have a 0 cm mark at the bottom and a 100 cm mark at the top.

wooden rod

stand

clamp

boss

springs

card

masses

bench

rule

stand

boss

Fig. 1.2

(ii) Adjust the rule until the 5.0 cm mark is level with the card as shown in Fig. 1.3.

5.0 cm mark

Fig. 1.3

4

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(c) (i) Pull the masses down so that the card is level with the 0 cm mark as shown in Fig. 1.4.

Release the masses and watch the movement of the masses and card. They will move up and down.

When the card returns to its lowest point for the first time, it has completed one cycle as shown in Fig. 1.4.

Gradually the card moves less and less and does not move down as far as the 0 cm mark.

5.0 cm mark

2.5 cm mark

0 cm mark

onecomplete

cycle

Fig. 1.4

(ii) Pull the masses down so that the card is again level with the 0 cm mark. Release the masses and count the number N of cycles for the card to reach the 2.5 cm mark at its lowest point.

N = .................................................. [1]

5


(d) (i) Remove the card from the mass hanger.

Use the compasses to draw a circle of approximate diameter 18 cm on the card.

Use the scissors to cut out the circle.

Measure and record the diameter d of the card.

d = ......................................................

(ii) Repeat (b) and (c).

N = ......................................................

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(e) Cut smaller circles and repeat (b) and (c) until you have six sets of values of d and N. Include in your table the two sets of values already taken.

Also include values of 1d

and N in your table.

[10]

(f) (i) Plot a graph of N on the y-axis against 1d

on the x-axis. [3]

(ii) Draw the straight line of best fit. [1]

(iii) Determine the gradient and y-intercept of this line.

gradient = ......................................................

y-intercept = ...................................................... [2]

7


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(g) It is suggested that the quantities N and d are related by the equation

N = Ad

+ B

where A and B are constants. Using your answers in (f)(iii), determine the values of A and B. Give appropriate units.

A = ......................................................

B = ...................................................... [2]

9



2 In this experiment, you will investigate the motion of a marble.

(a) (i) Balance the wooden rod on the pivot as shown in Fig. 2.1.

wooden rod

x

pivot

bench

P Q

holes

Fig. 2.1

(ii) Measure and record the distance x from the hole P to the pivot as shown in Fig. 2.1. Do not mark the wooden rod.

x = ............................................. m [2]

(b) (i) Calculate C using

C = x 2 + h 2x

where h = 0.100 m.

C = ............................................ m [1]

(ii) Justify the number of significant figures that you have given for your value of C.

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

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(c) (i) Set up the apparatus with the nail through hole P, as shown in Fig. 2.2.

boss nail

clamp

wooden rod

marble

wooden cube containerwith sand

stand

P

Q

bench

Fig. 2.2

The nail should be held in the clamp. The bottom of the wooden rod should be just above the top of the wooden cube. The marble should be in contact with the wooden rod.

11


(ii) Move the wooden rod to the left through a distance of 20 cm as shown in Fig. 2.3. Release the wooden rod. The wooden rod will move to the right and strike the marble.

20 cmsurfaceof sand

Fig. 2.3

Measure and record the horizontal distance R moved by the marble through the air.

R = .................................................. [2]

(iii) Estimate the percentage uncertainty in your value of R.

percentage uncertainty = .................................................. [1]

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(d) Using hole Q, repeat (a), (b)(i), (c)(i) and (c)(ii).

x = ...................................................m

C = ...................................................m

R = ......................................................[3]

(e) It is suggested that the relationship between C and R is

C = k

R 2

where k is a constant.

(i) Using your data, calculate two values of k.

first value of k = ......................................................

second value of k = ......................................................[1]

13


(ii) Explain whether your results in (e)(i) support the suggested relationship.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

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(f) (i) Describe four sources of uncertainty or limitations of the procedure for this experiment.

1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]

(ii) Describe four improvements that could be made to this experiment. You may suggest the use of other apparatus or different procedures.

1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]

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DC (AC/SG) 99938/3© UCLES 2015 [Turn over


*7004325696*

PHYSICS 9702/33


2 hours










1

2

Total

2

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1 In this experiment, you will investigate the equilibrium of a wooden rod.

(a) Set up the apparatus as shown in Fig. 1.1.

Fig. 1.1

The mass m should be 60 g. The string should be approximately half-way along the wooden rod. The spring should be horizontal.

(b) (i) Measure and record the length L of the coiled part of the spring.

L = ................................................. [1]

(ii) Measure and record the height h of the loop of the spring above the bench.

h = .....................................................

(iii) Measure and record the angle θ between the wooden rod and the bench.

θ = .....................................................°

3


(c) Change mass m to 80 g.

Adjust the position of the spring and string so that the length L is the same as in (b)(i) and the string is horizontal.

Repeat (b)(ii) and (b)(iii).

h = ......................................................

θ = .....................................................°[1]

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(d) (i) Copy your value of L from (b)(i). L = ......................................................

(ii) Change m and repeat (b)(ii) and (b)(iii) until you have six sets of values of m, h and θ.

For each value of m, adjust the position of the spring and string so that L is the same as in (d)(i) and the spring is horizontal.

Include your values from (b) and (c).

Also include values of hcos θ in your table.

[10]

(e) (i) Plot a graph of h

cos θ on the y-axis against m on the x-axis. [3]



gradient = ......................................................

y-intercept = ...................................................... [2]

5


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(f) The quantities h, θ and m are related by the equation

hcos θ

= Am + B

where A and B are constants.

Using your answers in (e)(iii), determine the values of A and B. Give appropriate units.

A = ......................................................

B = ...................................................... [2]

7



2 In this experiment, you will investigate the motion of a loaded wooden rod.

(a) (i) Set up the apparatus as shown in Fig. 2.1.

6 cmmass m2mass m1

yx

zwooden rod

spring

rod of clamp

rod of clamp

boss

boss

long string loop

bench

stands

Fig. 2.1

Support the wooden rod by passing it through the loop of the spring and the long string loop.

Mass m1 should be 200 g and mass m2 should be 100 g.

The bottom of mass m1 should be approximately 6 cm above the bench.

(ii) Adjust the apparatus until the wooden rod is balanced and horizontal. The spring and long string loop should be vertical.

8

9702/33/O/N/15© UCLES 2015

(iii) Measure and record the distances x, y and z as shown in Fig. 2.1, where

x is the distance between the loop above m1 and the spring loop, y is the distance between the spring loop and the long string loop, z is the distance between the long string loop and the loop above m2.

x = ......................................................

y = ......................................................

z = ...................................................... [2]

(iv) Estimate the percentage uncertainty in your value of y.

percentage uncertainty = ................................................. [1]

(b) Calculate C where

C = m1(x + y )2 + m2z 2.

C = ................................................. [1]

9


(c) (i) Pull the left side of the wooden rod down by 5 cm.

Release the wooden rod and watch the movement.

The wooden rod will move up and down again, completing a cycle as shown in Fig. 2.2.

onecomplete

cycle

Fig. 2.2

(ii) The time taken for one complete cycle is T.

By timing several of these complete cycles, determine an accurate value for T.

T = ................................................. [2]

(iii) Calculate T 2.

T 2 = ......................................................

(iv) Justify the number of significant figures that you have given for your value of T 2.

..................................................................................................................................

..................................................................................................................................

............................................................................................................................. [1]

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(d) Keeping distance y constant, change m2 to 50 g and repeat (a)(ii), (a)(iii), (b), (c)(i), (c)(ii) and (c)(iii).

x = ......................................................

y = ......................................................

z = ......................................................

C = ......................................................

T = ......................................................

T 2 = ...................................................... [3]

11


(e) It is suggested that the relationship between T and C is

T 2 = kC



first value of k = ......................................................

second value of k = ...................................................... [1]

(ii) Explain whether your results in (e)(i) support the suggested relationship.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

............................................................................................................................. [1]

12

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1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]


1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]





DC (AC/JG) 100011/3© UCLES 2015 [Turn over


*7086083758*

PHYSICS 9702/34


2 hours










1

2

Total

2

9702/34/O/N/15© UCLES 2015

BLANK PAGE

3



1 In this experiment, you will investigate forces in equilibrium.

(a) Assemble the apparatus as shown in Fig. 1.1. The angle θ should be approximately 150°. String AB should be parallel to the bench,

and the bottom of mass M should be approximately 10 cm above the bench.

standstand

mass

boss

spring nail

M

BA

string

10 cm

L

Fig. 1.1

(b) (i) Measure and record the angle θ between the string attached to mass M and the string attached to the spring, as shown in Fig. 1.1.

θ = ...............................................° [1]

(ii) Measure and record the length L of the coiled part of the spring, as shown in Fig. 1.1.

L = ................................................. [1]

(c) (i) Change the distance between the stands.

Adjust the height of A until string AB is parallel to the bench. If the apparatus is unstable, you may need to use the G-clamp to secure one of the stands to the bench.

(ii) Measure and record θ and L.

θ = .....................................................°

L = ......................................................

4

9702/34/O/N/15© UCLES 2015

(d) Repeat (c) until you have six sets of values of θ and L. Include your values from (b) and (c).

Also include values of 1

sin (θ –90°) in your table.

[10]

(e) (i) Plot a graph of 1

sin (θ –90°) on the y-axis against L on the x-axis. [3]



gradient = ......................................................

y-intercept = ...................................................... [2]

5


6

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(f) The quantities θ and L are related by the equation

1sin (θ –90°)

= a L + b

where a and b are constants.

Using your answers in (e)(iii), determine the values of a and b. Give appropriate units.

a = ......................................................

b = ...................................................... [2]

7



2 In this experiment, you will investigate the relationship between the performance of an electrical component and its volume.

(a) You are provided with two cylindrical components.

(i) Measure and record the diameter d and the length l of the larger cylindrical component, as shown in Fig. 2.1.

+d

l

Fig. 2.1

d = ......................................................

l = ...................................................... [2]

(ii) Calculate the volume V of the component using V = π d 2 l4

.

V = ................................................. [1]

(b) Justify the number of significant figures you have given for your value of V.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..................................................................................................................................... [1]

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(c) (i) Assemble the circuit shown in Fig. 2.2, using the larger cylindrical component. Ensure that the positive terminals are all connected as shown.

Switch on the power supply.

+

+

+

–S

cylindricalcomponent

powersupply

Fig. 2.2

(ii) Close switch S and watch the LED light up. Open switch S and watch the LED gradually go out.

(iii) Take measurements to find the time t between opening the switch S and the LED going out.

t = ................................................. [2]

(d) Estimate the percentage uncertainty in your value of t.

percentage uncertainty = ................................................ [1]

9


(e) Using the smaller cylindrical component, repeat (a) and (c).

d = ......................................................

l = ......................................................

V = ......................................................

t = ...................................................... [3]

(f) It is suggested that the relationship between t and V is

t = k V



first value of k = ......................................................

second value of k = ...................................................... [1]

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9702/34/O/N/15© UCLES 2015

(ii) Explain whether your results in (f)(i) support the suggested relationship.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

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(g) (i) Describe four sources of uncertainty or limitations of the procedure for this experiment.

1. ..............................................................................................................................

..................................................................................................................................

2. ..............................................................................................................................

..................................................................................................................................

3. ..............................................................................................................................

..................................................................................................................................

4. ..............................................................................................................................

.................................................................................................................................. [4]


1. ..............................................................................................................................

..................................................................................................................................

2. ..............................................................................................................................

..................................................................................................................................

3. ..............................................................................................................................

..................................................................................................................................

4. ..............................................................................................................................

.................................................................................................................................. [4]

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DC (ST/FD) 99994/4© UCLES 2015 [Turn over


*9015482900*

PHYSICS 9702/35


2 hours










1

2

Total

2

9702/35/O/N/15© UCLES 2015


1 In this experiment, you will investigate how the potential difference across a resistor changes as the resistance of the circuit is changed.

(a) (i) Set up the circuit shown in Fig. 1.1.

+ –

power supply

nail

wire

wooden strip A wooden strip B

a b

V

Fig. 1.1

The two crocodile clips attached to the wires on the wooden strips should be approximately half-way along each of the wires.

(ii) Measure and record the lengths a and b.

a = ......................................................

b = ...................................................... (iii) Calculate the value of C where C = a + b.

C = ......................................................

(iv) Close the switch. (v) Record the voltmeter reading V.

V = ...................................................... (vi) Open the switch.

3


(b) (i) Change the value of a. Measure and record this value of a.

a = .................................................. [1] (ii) Calculate the new value of b using b = C – a.

b = ......................................................

(iii) Change b to the value shown in (b)(ii).

(iv) Close the switch. (v) Record the voltmeter reading V.

V = .................................................. [1] (vi) Open the switch.

4

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(c) Repeat (b) until you have six sets of readings of a, b and V.

Include values of 1V

in your table.

[10] (d) (i) Plot a graph of 1

V on the y-axis against b on the x-axis. [3]

(ii) Draw the straight line of best fit. [1] (iii) Determine the gradient and y-intercept of this line.

gradient = ......................................................

y-intercept = ......................................................[2]

5


6

9702/35/O/N/15© UCLES 2015

(e) The quantities V and b are related by the equation

1V

= Pb + Q where P and Q are constants.

Using your answers in (d)(iii), determine values for P and Q. Give appropriate units.

P = ......................................................

Q = ......................................................[2]

7



2 In this experiment, you will investigate the motion of a magnetised object in a magnetic field. (a) You have been provided with a nail and two magnets.

Hold the head of the nail. Move one of the magnets as shown by the dotted path in Fig. 2.1.

S

head of nail

Fig. 2.1

The S pole of the magnet should remain in contact with the nail until it reaches the end of the nail. At the end of the nail, lift the magnet above the nail and back to the head.

Repeat 10 times.

The nail should not touch a magnet during the remainder of the experiment. If it does, you should re-magnetise the nail by repeating (a). (b) (i) Place the sheet of paper flat on the bench as shown in Fig. 2.2.

20 cm≈edge of bench

sheet of paper

spot

Fig. 2.2

8

9702/35/O/N/15© UCLES 2015

(ii) Set up the apparatus as shown in Fig. 2.3.

clampnail in loop

sheet of paper

protractor

boss

stand wooden rod

Fig. 2.3

Place the protractor on the line with its centre over the spot.

Align the rod so that the rod is directly above and parallel to the line on the sheet of paper.

Place the nail in the paper loop.

Suspend the loop from the rod. The nail will be perpendicular to the line on the sheet of paper.

The nail should be just above the protractor with the mark on the loop above the spot on the line. The loop should be free to rotate.

(iii) With the apparatus set up as shown in Fig. 2.3, position the magnets on the sheet

of paper as shown in Fig. 2.4.

N

S

N

S

x

x

Fig. 2.4

9


Move the magnets along the line until the nail rotates through approximately 45°. The magnets should each be the same distance x from the spot and should

remain in these positions throughout the experiment.

(iv) Measure and record x.

x = .................................................. [1]

(c) (i) Without removing the loop and nail, move the wooden rod so that the rod makes an angle θ of approximately 30° to the line on the sheet of paper as shown in Fig. 2.5.

N

S

N

S

θwooden rod

Fig. 2.5

The mark on the loop should be above the spot.

Measure and record θ.

θ = ................................................° [1]

(ii) Estimate the percentage uncertainty in your value of θ.


10

9702/35/O/N/15© UCLES 2015

(iii) Calculate cos2

2d nθ .

cos2 2d nθ = .................................................. [1]

(iv) Justify the number of significant figures that you have given for your value of

cos2 2d nθ .

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

(d) (i) Rotate the nail and loop through approximately 45°. Release the nail. It should complete a cycle as shown in Fig. 2.6.

one completecycle

Fig. 2.6 (ii) The time taken for one complete cycle is T.

By timing several of these complete cycles, determine an accurate value for T.

T = .................................................. [2]

11


(e) (i) Remove the nail from the loop and replace it in the loop the other way round.

(ii) Repeat (d) to obtain the time T taken for one complete cycle.

T = ...................................................... (iii) You have two values of T from (d)(ii) and (e)(ii).

One of your values of T will be shorter than the other. This is T1. The other value is T2. Record your values of T1 and T2 below.

shorter time T1 = ......................................................

longer time T2 = ...................................................... (iv) Calculate

T

T1

2

.

T

T1

2

= ......................................................

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(f) Repeat (c)(i), (c)(iii), (d) and (e) with the wooden rod at an angle θ of approximately 60°.

θ= .....................................................°

cos2 2d nθ = ......................................................

T = ......................................................

with nail other way round, T = ......................................................

shorter time T1 = ......................................................

longer time T2 = ......................................................

T

T1

2

= ...................................................... [3]

13


(g) It is suggested that the relationship between T1, T2 and θ is

T

T1

2

= k cos2 2d nθ

where k is a constant. (i) Using your data, calculate two values of k.

first value of k = ......................................................

second value of k = ......................................................[1]

(ii) Explain whether your results support the suggested relationship.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

14

9702/35/O/N/15© UCLES 2015

(h) (i) Describe four sources of uncertainty or limitations of the procedure for this experiment.

1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

..................................................................................................................................[4]

(ii) Describe four improvements that could be made to this experiment. You may

suggest the use of other apparatus or different procedures.

1. ...............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

..................................................................................................................................[4]

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DC (NH/FD) 99992/2© UCLES 2015 [Turn over

*1024956386*

PHYSICS 9702/36


2 hours











1

2

Total

2

9702/36/O/N/15© UCLES 2015


1 In this experiment, you will investigate the upthrust on an object partly immersed in water.

(a) Measure and record the height H of the flask, as shown in Fig. 1.1.

sand

bench

flask

wire loop

Fig. 1.1

H = ............................................ cm [1]

3


(b) Assemble the apparatus as shown in Fig. 1.2, with the bottom of the flask approximately 4 cm below the water surface.

4 cm

bw

water

bench

container

flask

newton-meter

watersurface

stand

clamp

boss

Fig. 1.2

(c) (i) Measure and record the height hw of the water surface above the bench, as shown in Fig. 1.2.

hw = ................................................. cm

(ii) Measure and record the height hb of the bottom of the flask above the bench, as shown in Fig. 1.2.

hb = ................................................. cm

(iii) Record the newton-meter reading F.

F = .............................................. N [1]

(iv) Calculate x, using x = hw – hb.

x = ............................................ cm [1]

4

9702/36/O/N/15© UCLES 2015

(d) Adjust the height of the boss and repeat (c) until you have six sets of values of hw, hb and F.

For all values of hb, the water surface should be in contact with the sloping sides of the flask.

Include values of x and (H – x)3 in your table.

[9]

(e) (i) Plot a graph of F on the y-axis against (H – x)3 on the x-axis. [3]



gradient = ......................................................

y-intercept = ...................................................... [2]

5


6

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(f) The quantities F, H and x are related by the equation

F = a (H – x)3 + b


Using your answers in (e)(iii), determine the values of a and b. Give appropriate units.

a = ......................................................

b = ...................................................... [2]

7



2 In this experiment, you will investigate the motion of a flywheel rolling down a ramp.

(a) You are provided with a small flywheel, as shown in Fig. 2.1.

flywheel

axle

Fig. 2.1

(i) Measure and record the diameter d of the axle.

d = ............................................ cm [1]

(ii) Measure and record the diameter D of the flywheel.

D = ............................................ cm [1]

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9702/36/O/N/15© UCLES 2015

(b) You have also been provided with a track. Set up the track with one end raised above the bench, as shown in Fig. 2.2.

markl

mark

track

boss

clamp

stand

bench

Fig. 2.2

The height h should be approximately 8 cm.

(i) Measure and record the length l of the track.

l = ......................................................

(ii) Measure and record the height h above the bench of the raised end of the track.

h = ......................................................

(iii) Measure and record the distance s between the two marks on the track.

s = ...................................................... [1]

9


(c) (i) Place the axle of the flywheel on the track at the upper mark as shown in Fig. 2.3. Release the flywheel and watch it roll down to the lower mark (the top of the

flywheel may need a gentle push to start it rolling).

mark

axle

finger

mark

bench

Fig. 2.3

(ii) Replace the axle of the flywheel on the track at the upper mark. Take measurements to find the time t taken for the flywheel to roll from the upper

mark to the lower mark.

t = .................................................. [2]

(iii) Estimate the percentage uncertainty in your value of t.


10

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(iv) Theory suggests that an approximate value for the acceleration of free fall g is given by

g = slD2

hd2t2.

Calculate a value for g. Give an appropriate unit.

g = .................................................. [1]

(d) (i) Push the two plastic tubes onto the axle to increase the diameter of the axle, as shown in Fig. 2.4.

Fig. 2.4

(ii) Repeat (a)(i) and (c)(ii).

d = ................................................. cm

t = ...................................................... [2]

11


(e) It is suggested that the relationship between t and d is

t = kd



first value of k = ......................................................

second value of k = ...................................................... [1]

(ii) Justify the number of significant figures you have given for your values of k.

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

(iii) Explain whether your results in (e)(i) support the suggested relationship.

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

.............................................................................................................................. [1]

12

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1. ..............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]


1. ..............................................................................................................................

..................................................................................................................................

2. ...............................................................................................................................

..................................................................................................................................

3. ...............................................................................................................................

..................................................................................................................................

4. ...............................................................................................................................

.................................................................................................................................. [4]


DC (ST/CGW) 97085/2© UCLES 2015 [Turn over

Cambridge International ExaminationsCambridge International Advanced Level

*5785590745*

PHYSICS 9702/41

Paper 4 A2 Structured Questions October/November 2015

2 hours









1

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12

Total

2

9702/41/O/N/15© UCLES 2015

Data




(

14πε0

= 8.99 × 109 m F–1)











3


Formulae


v2 = u2 + 2as





NmV

<c 2>



v = ± ω (x02 – x 2)










2

4

9702/41/O/N/15© UCLES 2015

Section A


1 A satellite of mass mS is in a circular orbit of radius x about the Earth.

The Earth may be considered to be an isolated uniform sphere with its mass M concentrated at its centre.

(a) (i) Show that the kinetic energy EK of the satellite is given by the expression

EK = GMmS

2x

where G is the gravitational constant. Explain your working.

[3]

(ii) State an expression, in terms of G, M, mS and x, for the potential energy EP of the satellite.

.......................................................................................................................................[1]

(iii) Using answers from (i) and (ii), derive an expression for the total energy ET of the satellite.

ET = ...........................................................[2]

5


(b) Small resistive forces acting on the satellite cause the radius of its circular orbit to change.

Use your answers in (a) to state, for the satellite, whether each of the following quantities increases, decreases or remains constant.

(i) total energy

.......................................................................................................................................[1]

(ii) radius of orbit

.......................................................................................................................................[1]

(iii) potential energy

.......................................................................................................................................[1]

(iv) kinetic energy

.......................................................................................................................................[1]

6

9702/41/O/N/15© UCLES 2015

2 (a) State what is meant by an ideal gas.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) The mean-square speed of the atoms of a fixed mass of an ideal gas at 32 °C is 1.9 × 106 m2 s–2.

The gas is heated at constant volume to a temperature of 80 °C.

Determine

(i) the rise, in kelvin, of the temperature of the gas,

temperature rise = ...................................................... K [1]

(ii) the root-mean-square (r.m.s.) speed of the atoms at 80 °C.

r.m.s. speed = ................................................ m s–1 [3]

7


3 (a) State an expression, in terms of work done and heating, that is used to calculate the increase in internal energy of a system.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) State and explain, in terms of your expression in (a), the change, if any, in the internal energy

(i) of the water in an ice cube when the ice melts, at atmospheric pressure, to form a liquid without any change of temperature,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) of the gas in a tyre when the tyre bursts so that the gas suddenly increases in volume. Assume that the gas is ideal.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

8

9702/41/O/N/15© UCLES 2015

4 (a) Distinguish between free oscillations and forced oscillations.

free oscillations: ........................................................................................................................

...................................................................................................................................................

forced oscillations: ....................................................................................................................

...................................................................................................................................................[2]

(b) A trolley is held on a horizontal surface by means of two stretched springs, as shown inFig. 4.1.

trolleyspring

oscillatorfixed point

spring

Fig. 4.1

One spring is attached to a fixed point. The other spring is attached to an oscillator that causes horizontal oscillations of the trolley.

The oscillator vibrates with a constant amplitude of vibration. The frequency of vibration of the oscillator is gradually increased from a very low value.

The variation with frequency f of the amplitude x0 of vibration of the trolley is shown inFig. 4.2.

1.5 2.0 2.5f / Hz

x0

3.0

Fig. 4.2

9


Use Fig. 4.2 to state and explain

(i) the value of the natural frequency of vibration of the trolley,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) whether there are any frictional forces acting on the trolley.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

(c) The oscillator in (b) is now stopped.

The trolley is given a horizontal displacement of 4.7 cm along the line of the springs. The trolley is then released.

Use information from Fig. 4.2 to estimate the maximum speed of the trolley.

speed = ................................................ m s–1 [2]

10

9702/41/O/N/15© UCLES 2015

5 A charged particle P is situated in a vacuum at a distance x from the centre of a charged conducting sphere of radius r, as illustrated in Fig. 5.1.

Pr

x

Fig. 5.1

For the particle P outside the conducting sphere, the charge on the sphere may be assumed to be a point charge at its centre.

(a) (i) State Coulomb’s law.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) The sphere and the particle P are both charged positively.

1. State the direction of the force acting on particle P.

.......................................................................................................................................[1]

2. State the position of particle P for the force to be maximum.

.......................................................................................................................................[1]

3. Determine the ratio

force on particle P at x = rforce on particle P at x = 4r

.

ratio = .......................................................... [2]

11


(b) When the charge on the sphere is 6.0 × 10–7 C, the electric field strength at the surface of the sphere is 1.5 × 106 V m–1.

Electrical breakdown (a spark) occurs when the electric field strength at the surface of the sphere exceeds 2.0 × 106 V m–1.

Determine the additional charge that may be added to the sphere before breakdown occurs.

charge = ...................................................... C [3]

12

9702/41/O/N/15© UCLES 2015

6 (a) A particle has mass m, charge +q and speed v.

State the magnitude and direction of the force, if any, on the particle when the particle is travelling along the direction of

(i) a uniform gravitational field of field strength g,

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) a uniform magnetic field of flux density B.

...........................................................................................................................................

.......................................................................................................................................[1]

(b) Two charged horizontal metal plates, situated in a vacuum, produce a uniform electric field of field strength E between the plates. The field strength outside the region between the plates is zero.

The particle in (a) enters the region of the electric field at right-angles to the direction of the field, as illustrated in Fig. 6.1.

E

vparticle,charge +qmass m

Fig. 6.1

A uniform magnetic field is to be applied in the same region as the electric field so that the particle passes undeviated through the region between the plates.

(i) State and explain the direction of the magnetic field.

...........................................................................................................................................

.......................................................................................................................................[2]

13


(ii) Derive, with explanation, the relation between the speed v and the magnitudes of the electric field strength E and the magnetic flux density B.

[3]

(c) A second particle has the same mass m and charge +q as that in (b) but its speed is 2v. This particle enters the region between the plates along the same direction as the particle

in (b).

On Fig. 6.1, sketch the path of this particle in the region between the plates. [2]

14

9702/41/O/N/15© UCLES 2015

7 (a) By reference to the photoelectric effect, state what is meant by the threshold frequency.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) Electrons are emitted from a metal surface when light of a particular wavelength is incident on the surface.

Explain why the emitted electrons have a range of values of kinetic energy below a maximum value.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(c) The wavelength of the incident radiation is λ. The variation with 1/λ of the maximum kinetic energy EMAX of electrons emitted from a metal

surface is shown in Fig. 7.1.

1.00

1.0

2.0

3.0

4.0

1.5 2.0 2.5

–

3.53.0

/ 106 m–1

EMAX

/ 10–19 J

1

Fig. 7.1

15


(i) Use Fig. 7.1 to determine, without reference to the work function energy, the threshold frequency f0.

f0 = .................................................... Hz [2]

(ii) Use your answer in (i) to calculate the work function energy Φ.

Φ = ....................................................... J [2]

(d) Caesium metal has a work function energy of 2.2 × 10–19 J.

On the axes of Fig. 7.1, sketch a graph to show the variation with 1/λ of EMAX for caesium metal. [2]

16

9702/41/O/N/15© UCLES 2015

8 (a) Distinguish, for an atom, between a nucleus and a nucleon.

nucleus: .....................................................................................................................................

...................................................................................................................................................

nucleon: ....................................................................................................................................

...................................................................................................................................................[3]

(b) Radon gas is a naturally occurring radioactive gas with a half-life of 3.8 days.

The activity of radon gas in a room is found to be 97 Bq in each 1.0 m3 of air.

(i) Calculate

1. the decay constant, in s–1, of radon,

decay constant = .................................................... s–1 [2]

2. the number of radon atoms giving rise to an activity of 97 Bq.

number = .......................................................... [2]

17


(ii) A volume of 2.5 × 10–2 m3 of air in the room contains 1.0 mol of molecules.

Determine the ratio, for 1.0 m3 of air,

number of radon atomsnumber of air molecules

.

ratio = .......................................................... [2]

18

9702/41/O/N/15© UCLES 2015

Section B


9 A battery of e.m.f. 6.0 V and negligible internal resistance is connected to three resistors, each of resistance 2.0 kΩ, and a thermistor, as shown in Fig. 9.1.

A B

2.0 k

2.0 k 2.0 k

6.0 V

Fig. 9.1

The thermistor has resistance 2.8 kΩ at 10 °C and resistance 1.8 kΩ at 20 °C.

(a) Calculate the potential

(i) at point A,

potential = ...................................................... V [1]

(ii) at point B for the thermistor at 10 °C,

potential = ...................................................... V [2]

19


(iii) at point B for the thermistor at 20 °C.

potential = ...................................................... V [1]

(b) The points A and B in Fig. 9.1 are connected to the inputs of an ideal operational amplifier (op-amp), as shown in Fig. 9.2.

+9 V

–9 V VOUT

A

B

–

+

Fig. 9.2

The thermistor is warmed from 10 °C to 20 °C. State and explain the change in the output potential VOUT of the op-amp as the thermistor is

warmed.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[4]

20

9702/41/O/N/15© UCLES 2015

10 (a) Explain what is meant by the sharpness and by the contrast of an X-ray image.

sharpness: ................................................................................................................................

...................................................................................................................................................

contrast: ....................................................................................................................................

...................................................................................................................................................[2]

(b) A parallel X-ray beam of intensity I is incident on a medium of thickness x, as illustrated in Fig. 10.1.

x

medium

incident

intensity I

transmitted

intensity IT

Fig. 10.1

The transmitted intensity is IT.

Data for the linear absorption (attenuation) coefficient μ for 80 keV X-rays in bone and in muscle are given in Fig. 10.2.

μ / cm–1

bonemuscle

3.00.27

Fig. 10.2

(i) State, with reference to the production of X-rays, what is meant by 80 keV X-rays.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

21


(ii) Calculate the ratio IT / I for 80 keV X-rays passing through a thickness of 1.4 cm of bone.

ratio = .......................................................... [2]

(c) An X-ray image of the upper leg of a student is produced. Part of the X-ray beam passes through a comparatively large thickness of muscle and part

through some muscle and the leg bone.

Use data from Fig. 10.2 to suggest whether the image has good contrast.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[3]

22

9702/41/O/N/15© UCLES 2015

11 A carrier wave is frequency modulated.

(a) Describe what is meant by frequency modulation.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) The sinusoidal carrier wave has a frequency of 750 kHz and an amplitude of 5.0 V. The carrier wave is frequency modulated by a sinusoidal signal of frequency 7.5 kHz and

amplitude 1.5 V. The frequency deviation of the carrier wave is 20 kHz V–1.

Determine, for the frequency-modulated carrier wave,

(i) the amplitude,

amplitude = ...................................................... V [1]

(ii) the minimum frequency,

minimum frequency = .................................................. kHz [1]

(iii) the maximum frequency,

maximum frequency = .................................................. kHz [1]

(iv) the number of times per second that the frequency changes from its minimum value to its maximum value and then back to the minimum value.

number = .................................................... s–1 [1]

23

9702/41/O/N/15© UCLES 2015

12 (a) When infra-red radiation passes along an optic fibre, it is attenuated.

(i) State what is meant by attenuation.

...........................................................................................................................................

.......................................................................................................................................[1]

(ii) The infra-red radiation is transmitted as a series of pulses.

State and explain two advantages of the digital, rather than the analogue, transmission of information.

1. ........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

2. ........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................[4]

(b) The input light power to an optic fibre of length 36 km is 145 mW. The output light power is 29 mW.

Calculate, in dB km–1, the attenuation per unit length of the optic fibre.

attenuation per unit length = ............................................. dB km–1 [2]

24

9702/41/O/N/15© UCLES 2015




BLANK PAGE


DC (GB) 116823© UCLES 2015 [Turn over


*6595352311*

PHYSICS 9702/42


2 hours









1

2

3

4

5

6

7

8

9

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12

Total

2

9702/42/O/N/15© UCLES 2015

Data




(

14πε0

= 8.99 × 109 m F–1)











3


Formulae


v2 = u2 + 2as





NmV

<c 2>



v = ± ω (x02 – x 2)










2

4

9702/42/O/N/15© UCLES 2015

Section A


1 A satellite of mass mS is in a circular orbit of radius x about the Earth.

The Earth may be considered to be an isolated uniform sphere with its mass M concentrated at its centre.

(a) (i) Show that the kinetic energy EK of the satellite is given by the expression

EK = GMmS

2x

where G is the gravitational constant. Explain your working.

[3]

(ii) State an expression, in terms of G, M, mS and x, for the potential energy EP of the satellite.

.......................................................................................................................................[1]

(iii) Using answers from (i) and (ii), derive an expression for the total energy ET of the satellite.

ET = ...........................................................[2]

5


(b) Small resistive forces acting on the satellite cause the radius of its circular orbit to change.

Use your answers in (a) to state, for the satellite, whether each of the following quantities increases, decreases or remains constant.

(i) total energy

.......................................................................................................................................[1]

(ii) radius of orbit

.......................................................................................................................................[1]

(iii) potential energy

.......................................................................................................................................[1]

(iv) kinetic energy

.......................................................................................................................................[1]

6

9702/42/O/N/15© UCLES 2015

2 (a) State what is meant by an ideal gas.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) The mean-square speed of the atoms of a fixed mass of an ideal gas at 32 °C is 1.9 × 106 m2 s–2.

The gas is heated at constant volume to a temperature of 80 °C.

Determine

(i) the rise, in kelvin, of the temperature of the gas,

temperature rise = ...................................................... K [1]

(ii) the root-mean-square (r.m.s.) speed of the atoms at 80 °C.

r.m.s. speed = ................................................ m s–1 [3]

7


3 (a) State an expression, in terms of work done and heating, that is used to calculate the increase in internal energy of a system.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) State and explain, in terms of your expression in (a), the change, if any, in the internal energy

(i) of the water in an ice cube when the ice melts, at atmospheric pressure, to form a liquid without any change of temperature,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) of the gas in a tyre when the tyre bursts so that the gas suddenly increases in volume. Assume that the gas is ideal.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

8

9702/42/O/N/15© UCLES 2015

4 (a) Distinguish between free oscillations and forced oscillations.

free oscillations: ........................................................................................................................

...................................................................................................................................................

forced oscillations: ....................................................................................................................

...................................................................................................................................................[2]

(b) A trolley is held on a horizontal surface by means of two stretched springs, as shown inFig. 4.1.

trolleyspring

oscillatorfixed point

spring

Fig. 4.1

One spring is attached to a fixed point. The other spring is attached to an oscillator that causes horizontal oscillations of the trolley.

The oscillator vibrates with a constant amplitude of vibration. The frequency of vibration of the oscillator is gradually increased from a very low value.

The variation with frequency f of the amplitude x0 of vibration of the trolley is shown inFig. 4.2.

1.5 2.0 2.5f / Hz

x0

3.0

Fig. 4.2

9


Use Fig. 4.2 to state and explain

(i) the value of the natural frequency of vibration of the trolley,

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[3]

(ii) whether there are any frictional forces acting on the trolley.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[1]

(c) The oscillator in (b) is now stopped.

The trolley is given a horizontal displacement of 4.7 cm along the line of the springs. The trolley is then released.

Use information from Fig. 4.2 to estimate the maximum speed of the trolley.

speed = ................................................ m s–1 [2]

10

9702/42/O/N/15© UCLES 2015

5 A charged particle P is situated in a vacuum at a distance x from the centre of a charged conducting sphere of radius r, as illustrated in Fig. 5.1.

Pr

x

Fig. 5.1

For the particle P outside the conducting sphere, the charge on the sphere may be assumed to be a point charge at its centre.

(a) (i) State Coulomb’s law.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) The sphere and the particle P are both charged positively.

1. State the direction of the force acting on particle P.

.......................................................................................................................................[1]

2. State the position of particle P for the force to be maximum.

.......................................................................................................................................[1]

3. Determine the ratio

force on particle P at x = rforce on particle P at x = 4r

.

ratio = .......................................................... [2]

11


(b) When the charge on the sphere is 6.0 × 10–7 C, the electric field strength at the surface of the sphere is 1.5 × 106 V m–1.

Electrical breakdown (a spark) occurs when the electric field strength at the surface of the sphere exceeds 2.0 × 106 V m–1.

Determine the additional charge that may be added to the sphere before breakdown occurs.

charge = ...................................................... C [3]

12

9702/42/O/N/15© UCLES 2015

6 (a) A particle has mass m, charge +q and speed v.

State the magnitude and direction of the force, if any, on the particle when the particle is travelling along the direction of

(i) a uniform gravitational field of field strength g,

...........................................................................................................................................

.......................................................................................................................................[2]

(ii) a uniform magnetic field of flux density B.

...........................................................................................................................................

.......................................................................................................................................[1]

(b) Two charged horizontal metal plates, situated in a vacuum, produce a uniform electric field of field strength E between the plates. The field strength outside the region between the plates is zero.

The particle in (a) enters the region of the electric field at right-angles to the direction of the field, as illustrated in Fig. 6.1.

E

vparticle,charge +qmass m

Fig. 6.1

A uniform magnetic field is to be applied in the same region as the electric field so that the particle passes undeviated through the region between the plates.

(i) State and explain the direction of the magnetic field.

...........................................................................................................................................

.......................................................................................................................................[2]

13


(ii) Derive, with explanation, the relation between the speed v and the magnitudes of the electric field strength E and the magnetic flux density B.

[3]

(c) A second particle has the same mass m and charge +q as that in (b) but its speed is 2v. This particle enters the region between the plates along the same direction as the particle

in (b).

On Fig. 6.1, sketch the path of this particle in the region between the plates. [2]

14

9702/42/O/N/15© UCLES 2015

7 (a) By reference to the photoelectric effect, state what is meant by the threshold frequency.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) Electrons are emitted from a metal surface when light of a particular wavelength is incident on the surface.

Explain why the emitted electrons have a range of values of kinetic energy below a maximum value.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(c) The wavelength of the incident radiation is λ. The variation with 1/λ of the maximum kinetic energy EMAX of electrons emitted from a metal

surface is shown in Fig. 7.1.

1.00

1.0

2.0

3.0

4.0

1.5 2.0 2.5

–

3.53.0

/ 106 m–1

EMAX

/ 10–19 J

1

Fig. 7.1

15


(i) Use Fig. 7.1 to determine, without reference to the work function energy, the threshold frequency f0.

f0 = .................................................... Hz [2]

(ii) Use your answer in (i) to calculate the work function energy Φ.

Φ = ....................................................... J [2]

(d) Caesium metal has a work function energy of 2.2 × 10–19 J.

On the axes of Fig. 7.1, sketch a graph to show the variation with 1/λ of EMAX for caesium metal. [2]

16

9702/42/O/N/15© UCLES 2015

8 (a) Distinguish, for an atom, between a nucleus and a nucleon.

nucleus: .....................................................................................................................................

...................................................................................................................................................

nucleon: ....................................................................................................................................

...................................................................................................................................................[3]

(b) Radon gas is a naturally occurring radioactive gas with a half-life of 3.8 days.

The activity of radon gas in a room is found to be 97 Bq in each 1.0 m3 of air.

(i) Calculate

1. the decay constant, in s–1, of radon,

decay constant = .................................................... s–1 [2]

2. the number of radon atoms giving rise to an activity of 97 Bq.

number = .......................................................... [2]

17


(ii) A volume of 2.5 × 10–2 m3 of air in the room contains 1.0 mol of molecules.

Determine the ratio, for 1.0 m3 of air,

number of radon atomsnumber of air molecules

.

ratio = .......................................................... [2]

18

9702/42/O/N/15© UCLES 2015

Section B


9 A battery of e.m.f. 6.0 V and negligible internal resistance is connected to three resistors, each of resistance 2.0 kΩ, and a thermistor, as shown in Fig. 9.1.

A B

2.0 k

2.0 k 2.0 k

6.0 V

Fig. 9.1

The thermistor has resistance 2.8 kΩ at 10 °C and resistance 1.8 kΩ at 20 °C.

(a) Calculate the potential

(i) at point A,

potential = ...................................................... V [1]

(ii) at point B for the thermistor at 10 °C,

potential = ...................................................... V [2]

19


(iii) at point B for the thermistor at 20 °C.

potential = ...................................................... V [1]

(b) The points A and B in Fig. 9.1 are connected to the inputs of an ideal operational amplifier (op-amp), as shown in Fig. 9.2.

+9 V

–9 V VOUT

A

B

–

+

Fig. 9.2

The thermistor is warmed from 10 °C to 20 °C. State and explain the change in the output potential VOUT of the op-amp as the thermistor is

warmed.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[4]

20

9702/42/O/N/15© UCLES 2015

10 (a) Explain what is meant by the sharpness and by the contrast of an X-ray image.

sharpness: ................................................................................................................................

...................................................................................................................................................

contrast: ....................................................................................................................................

...................................................................................................................................................[2]

(b) A parallel X-ray beam of intensity I is incident on a medium of thickness x, as illustrated in Fig. 10.1.

x

medium

incident

intensity I

transmitted

intensity IT

Fig. 10.1

The transmitted intensity is IT.

Data for the linear absorption (attenuation) coefficient μ for 80 keV X-rays in bone and in muscle are given in Fig. 10.2.

μ / cm–1

bonemuscle

3.00.27

Fig. 10.2

(i) State, with reference to the production of X-rays, what is meant by 80 keV X-rays.

...........................................................................................................................................

...........................................................................................................................................

.......................................................................................................................................[2]

21


(ii) Calculate the ratio IT / I for 80 keV X-rays passing through a thickness of 1.4 cm of bone.

ratio = .......................................................... [2]

(c) An X-ray image of the upper leg of a student is produced. Part of the X-ray beam passes through a comparatively large thickness of muscle and part

through some muscle and the leg bone.

Use data from Fig. 10.2 to suggest whether the image has good contrast.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[3]

22

9702/42/O/N/15© UCLES 2015

11 A carrier wave is frequency modulated.

(a) Describe what is meant by frequency modulation.

...................................................................................................................................................

...................................................................................................................................................

...............................................................................................................................................[2]

(b) The sinusoidal carrier wave has a frequency of 750 kHz and an amplitude of 5.0 V. The carrier wave is frequency modulated by a sinusoidal signal of frequency 7.5 kHz and

amplitude 1.5 V. The frequency deviation of the carrier wave is 20 kHz V–1.

Determine, for the frequency-modulated carrier wave,

(i) the amplitude,

amplitude = ...................................................... V [1]

(ii) the minimum frequency,

minimum frequency = .................................................. kHz [1]

(iii) the maximum frequency,

maximum frequency = .................................................. kHz [1]

(iv) the number of times per second that the frequency changes from its minimum value to its maximum value and then back to the minimum value.

number = .................................................... s–1 [1]

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12 (a) When infra-red radiation passes along an optic fibre, it is attenuated.

(i) State what is meant by attenuation.

...........................................................................................................................................

.......................................................................................................................................[1]

(ii) The infra-red radiation is transmitted as a series of pulses.

State and explain two advantages of the digital, rather than the analogue, transmission of information.

1. ........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

2. ........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................[4]

(b) The input light power to an optic fibre of length 36 km is 145 mW. The output light power is 29 mW.

Calculate, in dB km–1, the attenuation per unit length of the optic fibre.

attenuation per unit length = ............................................. dB km–1 [2]

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BLANK PAGE


DC (NF/CGW) 97089/2© UCLES 2015 [Turn over


*6110056757*

PHYSICS 9702/43


2 hours









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Data




(

14πε0

= 8.99 × 109 m F–1)











3


Formulae


v2 = u2 + 2as





NmV

<c 2>



v = ± ω (x02 – x 2)










2

4

9702/43/O/N/15© UCLES 2015

Section A


1 (a) State Newton’s law of gravitation.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]

(b) Some of the planets in the Solar System have several moons (satellites) that have circular orbits about the planet.

The planet and each of its moons may be considered to be point masses.

Show that the radius x of a moon’s orbit is related to the period T of the orbit by the expression

GM = 4π2x3

T 2

where G is the gravitational constant and M is the mass of the planet. Explain your working.

[3]

5


(c) The planet Neptune has eight moons, each in a circular orbit of radius x and period T. The variation with T 2 of x3 for some of the moons is shown in Fig. 1.1.

0.10

1.0

2.0

3.0

4.0

x 3 / 1014 km3

T 2 / day2

5.0

0.20 0.3 0.4

Fig. 1.1

Use Fig. 1.1 and the expression in (b) to determine the mass of Neptune.

mass = ................................................... kg [4]

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9702/43/O/N/15© UCLES 2015

2 (a) An ideal gas is said to consist of molecules that are hard elastic identical spheres.

State two further assumptions of the kinetic theory of gases.

1. ..............................................................................................................................................

...................................................................................................................................................

2. ..............................................................................................................................................

...................................................................................................................................................[2]

(b) The number of molecules per unit volume in an ideal gas is n.

If it is assumed that all the molecules are moving with speed v, the pressure p exerted by the gas on the walls of the vessel is given by

p = 13nmv2

where m is the mass of one molecule.

Explain the reasoning by which this expression is modified to give the formula

p = 13nm<c2>.

...................................................................................................................................................

.............................................................................................................................................. [1]

(c) The density of an ideal gas is 1.2 kg m−3 at a pressure of 1.0 × 105 Pa and a temperature of 27 °C.

(i) Calculate the root-mean-square (r.m.s.) speed of the molecules of the gas at 27 °C.

r.m.s. speed = ................................................. m s−1 [3]

7


(ii) Calculate the mean-square speed of the molecules at 207 °C.

mean-square speed = ............................................. m2 s−2 [2]

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3 (a) Two bodies are in thermal equilibrium.

State what is meant by thermal equilibrium.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]

(b) The temperature of a body is found to increase from 15.9 °C to 57.2 °C.

Determine, in kelvin and to an appropriate number of decimal places,

(i) the rise in temperature of the body,

temperature rise = ..................................................... K [1]

(ii) the final temperature.

temperature = ..................................................... K [1]

(c) An ideal gas at a constant pressure of 1.2 × 105 Pa is heated from a temperature of 290 K to a final temperature of 350 K. The change in volume of the gas is 950 cm3.

The total change in kinetic energy ΔEK, measured in joules, of the gas molecules is given by the expression

ΔEK = 32 × 1.9 × ΔT

where ΔT is the change in temperature in kelvin.

Determine the thermal energy required to produce the change in temperature from 290 K to 350 K.

energy = ...................................................... J [4]

9


4 (a) Define simple harmonic motion.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]

(b) A tube, sealed at one end, has a circular cross-sectional area A of 4.9 × 10−4 m2. Some sand is put in the tube so that the total mass M of the tube and its contents is 70 g. The tube floats upright in a liquid, as shown in Fig. 4.1.

sand

liquid

tubecross-sectional area A4.9 × 10–4 m2

h

Fig. 4.1

The liquid has a density ρ of 0.79 g cm−3.

By reference to the liquid pressure exerted on the base of the tube, show that the distance h of the base of the tube below the liquid surface is 18 cm. Explain your working.

[2]

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(c) The tube in (b) is displaced vertically and then released. The variation with time t of the distance h is shown in Fig. 4.2.

15

17

18

20

16

19

21

h / cm

t 10 t 2 t 3 t 4 t

Fig. 4.2

The system oscillates with simple harmonic motion of angular frequency ω given by the expression

ω2 = ρAgM

where g is the acceleration of free fall.

(i) Use data from (b) to determine

1. the time t1,

t1 = ...................................................... s [3]

2. the time t3.

t3 = ...................................................... s [1]

11


(ii) Determine the loss in total energy of the oscillating system between time t = 0 and time t = t4.

loss in energy = ...................................................... J [3]

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9702/43/O/N/15© UCLES 2015

5 A positively charged solid metal sphere is isolated in space. The electric field strength E is measured for different distances x from the centre of the sphere. The variation with x of the field strength E is shown in Fig. 5.1.

50

20

40

60

80

x / cm

E / N C–1

100

100 15 20 25

Fig. 5.1

(a) Suggest why, for values of x less than 4.0 cm, the electric field strength is zero.

...................................................................................................................................................

...................................................................................................................................................

............................................................................................................................................. [2]

(b) A point charge of +8.5 × 10−9 C moves from a point where x = 7.0 cm to a point where x = 5.0 cm.

Use Fig. 5.1 to estimate the change in electric potential energy of this point charge.

energy = ...................................................... J [3]

13


6 Suggest an explanation for each of the following observations.

(a) Two wires are laid side-by-side and carry equal currents I in opposite directions, as shown in Fig. 6.1.

I

I

Fig. 6.1

The total magnetic flux density due to the current in the wires is negligible.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [3]

(b) An air-cored solenoid is connected in series with a battery, as shown in Fig. 6.2.

solenoidiron core

Fig. 6.2

As an iron core is inserted into the solenoid, an e.m.f. that opposes the e.m.f. of the battery is induced in the solenoid.

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [4]

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7 A student is using a power supply that produces a sinusoidal output. The meters on the supply show that the output voltage V has a root-mean-square (r.m.s.) value of 14 V with a frequency of 750 Hz.

The variation with time t of the output voltage V may be represented by the expression

V = V0 sinωt.

(a) Determine the value of

(i) V0,

V0 = ..................................................... V [1]

(ii) ω.

ω = ............................................. rad s−1 [1]

(b) A capacitor with a large capacitance is connected across the terminals of the supply.

Suggest and explain why this may lead to a large current from the supply.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [3]

15


8 Light of wavelength λ is incident on a metal surface having a work function energy Φ.

Photoelectrons of maximum kinetic energy EMAX are emitted from the surface.

(a) State an equation relating Φ, EMAX and λ. Explain any other symbols you use.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]

(b) The variation with 1/λ of EMAX is shown in Fig. 8.1.

0

EMAX

1/

Fig. 8.1

(i) By reference to your answer in (a), explain why the gradient of the line does not depend on the metal surface.

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

(ii) The work function energy of sodium is 2.28 eV.

Determine the minimum wavelength λ0 at which EMAX is zero.

λ0 = .................................................... m [3]

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9 (a) State what is meant by the binding energy of a nucleus.

...................................................................................................................................................

...................................................................................................................................................

.............................................................................................................................................. [2]

(b) Data for two isotopes of uranium are given in Fig. 9.1.

isotope binding energy per nucleon / MeV binding energy / MeV

uranium-235

uranium-238

7.59

.............................

.............................

1802

Fig. 9.1

(i) State what is meant by isotopes.

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

(ii) Complete Fig. 9.1. [2]

(c) Uranium-235 has a half-life of 7.1 × 108 years.

(i) Show that the decay constant λ of uranium-235 is 3.1 × 10−17 s−1.

[1]

17


(ii) A sample of uranium-235 has an activity of 5.0 × 103 Bq.

Calculate the mass of the sample.

mass = ..................................................... g [3]

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BLANK PAGE

19


Section B


10 The output potential VOUT from an operational amplifier is to be monitored using an output device. The output VOUT can be either +5 V or −5 V.

(a) On Fig. 10.1, draw a circuit for the output device that consists of two light-emitting diodes B and G.

Diode B alone is to emit light when VOUT is +5 V. Diode G alone is to emit light when VOUT is −5 V.

VOUT

Fig. 10.1[3]

(b) On Fig. 10.2, draw a circuit of the output device that consists of a relay and a diode such that a high-power lamp is switched on only when VOUT is −5 V.

VOUT

high powerlamp

power supply

Fig. 10.2[4]

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9702/43/O/N/15© UCLES 2015

11 (a) An X-ray source is placed on one side of a metal plate, as shown in Fig. 11.1.

A BX-ray

source

metalplate

Fig. 11.1

The intensity of the X-ray beam is measured at points A and B.

State two reasons, other than absorption of X-ray photons in the metal, for the intensity at point A to be different to that at point B.

1. ..............................................................................................................................................

...................................................................................................................................................

2. ..............................................................................................................................................

...................................................................................................................................................[2]

(b) A specimen of muscle and bone undergoes X-ray examination. Parallel beams of X-rays are incident on the specimen, as shown in Fig. 11.2.

4.0 cmmuscle

X-raybeams

bone1.5 cm

Fig. 11.2

The specimen has a total thickness of 4.0 cm. One section contains a bone of thickness 1.5 cm.

Data for the linear absorption (attenuation) coefficient μ for the bone and for the muscle in the specimen are given in Fig. 11.3.

μ / cm−1

bonemuscle

3.00.27

Fig. 11.3

21


(i) Calculate the ratio

intensity of X-ray beam incident on the specimenintensity of X-ray beam emerging from the specimen

for the beam passing through

1. the 4.0 cm thickness of muscle alone,

ratio = ......................................................... [2]

2. the bone and the muscle.

ratio = ......................................................... [2]

(ii) Using your answers in (i), suggest and explain whether an X-ray image of this specimen is likely to have good contrast.

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

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12 A transmission system for speech may be represented by the block diagram of Fig. 12.1.

P

analogue-to-digital

converter

parallel-to-serial

converter

QX Y Z

Fig. 12.1

(a) Name the component labelled

(i) block X,

...................................................................................................................................... [1]

(ii) block Y,

...................................................................................................................................... [1]

(iii) Z.

...................................................................................................................................... [1]

(b) The variation with time of part of the signal at the input P to the analogue-to-digital converter (ADC) is shown in Fig. 12.2.

0.250

4

8

12

16

signal/ mV

time / ms

2

6

10

14

0.500 0.75 1.00 1.25 1.50 1.75

Fig. 12.2

23


Each number of the output from the ADC is a digital number where the smallest bit represents 1 mV.

State

(i) the minimum number of bits in each digital number so that the signal in Fig. 12.2 can be sampled fully,

number = ......................................................... [1]

(ii) the digital number produced by the ADC at time 0.50 ms.

number = ......................................................... [1]

(c) The ADC samples the signal in Fig. 12.2 at a frequency of 4.0 kHz. The first sample is taken at time zero.

Using data from Fig. 12.2, draw, on the axes of Fig. 12.3, the variation with time of the output at point Q for time zero to time 1.5 ms.

0.250

4

8

12

16

outputlevel

time / ms

2

6

10

14

0.500 0.75 1.00 1.25 1.50 1.75

Fig. 12.3[4]

Please turn over for Question 13.

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9702/43/O/N/15© UCLES 2015

13 Polar orbiting satellites have orbits over the poles of the Earth. Geostationary satellites are in equatorial orbits. Both are used as part of communication channels.

(a) State one advantage and one disadvantage of the use of a polar orbiting satellite as compared with a geostationary satellite.

advantage: ................................................................................................................................

...................................................................................................................................................

disadvantage: ............................................................................................................................

...................................................................................................................................................[2]

(b) A geostationary satellite is known to operate on the 6/4 GHz band.

Explain

(i) what is meant by the 6/4 GHz band,

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]

(ii) why two different frequencies are necessary.

...........................................................................................................................................

...........................................................................................................................................

...........................................................................................................................................

...................................................................................................................................... [2]





DC (LEG/FD) 97178/3© UCLES 2015 [Turn over


*9328967468*

PHYSICS 9702/51

Paper 5 Planning, Analysis and Evaluation October/November 2015

1 hour 15 minutes








2

9702/51/O/N/15© UCLES 2015

1 A student is investigating the angle at which a glass cylinder containing oil topples, as shown in Fig. 1.1.

bench

oil

glass cylinder

Fig. 1.1

A cylinder containing a mass m of oil can be tilted through a maximum angle φ from the vertical before it topples.

It is suggested that the relationship between m and φ is

1tan φ

= amρd 3

+ b

where d is the diameter of the cylinder, ρ is the density of the oil and a and b are constants.

Design a laboratory experiment to test the relationship between φ and m. Explain how your results could be used to determine values for a and b. You should draw a diagram, on page 3, showing the arrangement of your equipment. In your account you should pay particular attention to

(a) the procedure to be followed,

(b) the measurements to be taken,

(c) the control of variables,

(d) the analysis of the data,

(e) the safety precautions to be taken. [15]

3


Diagram

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Defining the problem

Methods ofdata collection

Method of analysis

Safety considerations

Additional detail

5


2 A student is investigating an electrical circuit containing a length of nichrome wire.

The circuit is set up as shown in Fig. 2.1.

E

A

I

L nichrome wire

Fig. 2.1

The length L of the wire in the circuit is varied and the current I is measured.

It is suggested that I and L are related by the equation

1I

= 4ρLπEd 2

+ rE

where E is the e.m.f. of the battery, d is the diameter of the wire and ρ and r are constants.

(a) A graph is plotted of 1I

on the y-axis against L on the x-axis.

Determine expressions for the gradient and y-intercept.

gradient = ......................................................

y-intercept = ...................................................... [1]

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9702/51/O/N/15© UCLES 2015

(b) Values of L and I are given in Fig. 2.2.

L / 10–2 m I / A

40.0 0.24 ± 0.01

48.0 0.20 ± 0.01

60.0 0.17 ± 0.01

70.0 0.15 ± 0.01

80.0 0.13 ± 0.01

92.0 0.12 ± 0.01

Fig. 2.2

Calculate and record values of 1I

/ A–1 in Fig. 2.2.

Include the absolute uncertainties in 1I

/ A–1. [3]

(c) (i) Plot a graph of 1I

/ A–1 against L / 10–2 m.

Include error bars for 1I

/ A–1. [2]

(ii) Draw the straight line of best fit and a worst acceptable straight line on your graph. Both lines should be clearly labelled. [2]

(iii) Determine the gradient of the line of best fit. Include the absolute uncertainty in your answer.

gradient = ................................................. [2]

7


1I /

/

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9702/51/O/N/15© UCLES 2015

(iv) Determine the y-intercept of the line of best fit. Include the absolute uncertainty in your answer.

y-intercept = ................................................. [2]

(d) (i) Using your answers to (a), (c)(iii) and (c)(iv), determine the values of ρ and r. Include appropriate units.

Data: E = 3.2 ± 0.1 V and d = 0.31 ± 0.01 mm.

ρ = ......................................................

r = ...................................................... [2]

(ii) Determine the percentage uncertainty in ρ.

percentage uncertainty in ρ = ............................................. % [1]



DC (GB) 117226© UCLES 2015 [Turn over


*0427580711*

PHYSICS 9702/52


1 hour 15 minutes








2

9702/52/O/N/15© UCLES 2015

1 A student is investigating the angle at which a glass cylinder containing oil topples, as shown in Fig. 1.1.

bench

oil

glass cylinder

Fig. 1.1

A cylinder containing a mass m of oil can be tilted through a maximum angle φ from the vertical before it topples.

It is suggested that the relationship between m and φ is

1tan φ

= amρd 3

+ b

where d is the diameter of the cylinder, ρ is the density of the oil and a and b are constants.

Design a laboratory experiment to test the relationship between φ and m. Explain how your results could be used to determine values for a and b. You should draw a diagram, on page 3, showing the arrangement of your equipment. In your account you should pay particular attention to






3


Diagram

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Method of analysis


Additional detail

5


2 A student is investigating an electrical circuit containing a length of nichrome wire.

The circuit is set up as shown in Fig. 2.1.

E

A

I

L nichrome wire

Fig. 2.1

The length L of the wire in the circuit is varied and the current I is measured.

It is suggested that I and L are related by the equation

1I

= 4ρLπEd 2

+ rE

where E is the e.m.f. of the battery, d is the diameter of the wire and ρ and r are constants.

(a) A graph is plotted of 1I

on the y-axis against L on the x-axis.

Determine expressions for the gradient and y-intercept.

gradient = ......................................................

y-intercept = ...................................................... [1]

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9702/52/O/N/15© UCLES 2015

(b) Values of L and I are given in Fig. 2.2.

L / 10–2 m I / A

40.0 0.24 ± 0.01

48.0 0.20 ± 0.01

60.0 0.17 ± 0.01

70.0 0.15 ± 0.01

80.0 0.13 ± 0.01

92.0 0.12 ± 0.01

Fig. 2.2

Calculate and record values of 1I

/ A–1 in Fig. 2.2.

Include the absolute uncertainties in 1I

/ A–1. [3]

(c) (i) Plot a graph of 1I

/ A–1 against L / 10–2 m.

Include error bars for 1I

/ A–1. [2]



gradient = ................................................. [2]

7


1I /

/

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9702/52/O/N/15© UCLES 2015

(iv) Determine the y-intercept of the line of best fit. Include the absolute uncertainty in your answer.

y-intercept = ................................................. [2]

(d) (i) Using your answers to (a), (c)(iii) and (c)(iv), determine the values of ρ and r. Include appropriate units.

Data: E = 3.2 ± 0.1 V and d = 0.31 ± 0.01 mm.

ρ = ......................................................

r = ...................................................... [2]

(ii) Determine the percentage uncertainty in ρ.

percentage uncertainty in ρ = ............................................. % [1]



DC (LEG/FD) 97183/3© UCLES 2015 [Turn over


*9820037802*

PHYSICS 9702/53


1 hour 15 minutes








2

9702/53/O/N/15© UCLES 2015

1 A beaker contains water and some metal blocks as shown in Fig. 1.1.

heaterwater

metal block

metal block

Fig. 1.1

A student uses an electrical heater to produce a particular temperature increase in the water.

It is suggested that the electrical energy E supplied to the heater is related to the mass m of metal blocks by the relationship

E = am + b


Design a laboratory experiment to test the relationship between E and m. Explain how your results could be used to determine values for a and b. You should draw a diagram, on page 3, showing the arrangement of your equipment. In your account you should pay particular attention to






3


Diagram

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Method of analysis


Additional detail

5


2 A student is investigating circular motion.

A small mass m attached to a larger mass P is rotated at constant speed in a horizontal circle, as shown in Fig. 2.1.

P

m

rigid tube

string

r

Fig. 2.1

The student changes the radius r of the circle and measures the time t for ten revolutions. The student then determines the period T of a revolution and then the speed v.

It is suggested that v and r are related by the equation

Pg = mv 2

r

where g is the acceleration of free fall.

(a) A graph is plotted of v 2 on the y-axis against r on the x-axis. Determine an expression for the gradient.

gradient = .................................................. [1]

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(b) The speed v is given by

v = 2πrT

.

Values of r and t are given in Fig. 2.2.

r / m t / s

0.160 3.4 ± 0.2

0.280 4.0 ± 0.2

0.400 4.8 ± 0.2

0.520 5.4 ± 0.2

0.640 6.0 ± 0.2

0.760 6.6 ± 0.2

Fig. 2.2

Calculate and record values of T / s, v / m s–1 and v 2 / m 2 s–2 in Fig. 2.2. Include the absolute uncertainties in v 2. [3]

(c) (i) Plot a graph of v 2 / m 2 s–2 against r / m. Include error bars for v 2. [2]



gradient = .................................................. [2]

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9702/53/O/N/15© UCLES 2015

(d) (i) Using your answers to (a) and (c)(iii), determine the value of P. Include an appropriate unit.

Data: g = 9.81 m s–2 and m = 0.025 ± 0.001 kg.

P = .................................................. [2]

(ii) Determine the percentage uncertainty in your value of P.

percentage uncertainty = ............................................. % [1]

(e) (i) The experiment is repeated with a small mass m of 0.040 kg. Determine the speed v when the radius r is 0.500 ± 0.005 m.

v = .........................................m s–1 [1]

(ii) Determine the percentage uncertainty in your value of v.

percentage uncertainty = ............................................. % [1]


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