JC2 H2 Common Test

8/14/2019 JC2 H2 Common Test

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DATA AND FORMULAEDataspeed of light in free space,permeability of free space,permittivity of free space,elementary charge,the Planck constant,unified atomic mass constant,rest mass of electron,rest mass of proton,molar gas constant,the Avogadro con$tant,the Boltzmann constant,gravitational consiant,acceleration of free fall,

Formulaeuniformly accelerated motion,

work done on/by a gas,hydrostatic pressure,gravitational potential,displacement of particle in s.h.m.,velocity of particle in s. h.m.,resistors in series,resistors in parallel,electric potential,alternatinq currenvvoltage,transmission coefficient,

radioactive decay,decay constant,

3.oox1o3ms147rx107Hm18.85x10-12Fm1(1 / (36rr)) x10'gFmr1.60 x 10 le c6.63x1034Js1.66 x 10 'z7 kg9.11 x 10 31 kg1 .67 x 10-27 kg8.31 JKlmol 16.02 x 1023 mol-11.38 x 10 '?3 J Kr6.67 x 1o 11 N m2 kg-'9.81 ms 2

.2

0

R

T

I

ut+%a(u2 + 2aspavpghGmxo sin rdfvacosaltorJU; x'JR1 +R2+1lR1+ 1lR2+ .Q / 4ntorxasin.' texp(-2kd)

xa exp(-.lt)0 693

8n'n(LJ - E)


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Section AAnswer all questions

Six molecules are moving with the speeds and directions shown.+--o250 m s-1

Ct---'300 m s-l

Ct_+450 m s-1

+-O450 m s'r O*500 m s'

What is the root mean square speed of these molecules?359ms1 367ms1 381 m s1 400msr

2 A balloon with a volume of 4OOO cm3 contains helium at a pressure of 1 .20 x 105 Pa.How many moles of helium are in the balloon if each helium atom has an averagekinetic energy of 3.6O x 10'22 J?A 1.1',| B 1.44 c 2.22 D 332

3 A gas with molecular mass of M at a temperature f has a root-mean-square speedof c/. Another gas with tvuice the molecular mass and at three times the temperaturehas a root-mean-square speed of c2. What is lhe .atio c1/c2?

The graph below shows the variation of temperature with time for 1 kg of asubstance. The substance is initially a solid, and is heated at a constant rate until allof it vapourises. At any point, any vapour formed is allowed to escape freely out ofthe container.

"6E!6

250 m s-r

Temperature / oC

Tr


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Which of the following statements is correct?A The latent heat of fusion is greater than the latent heat of vapourisation.B The amount of energy required to vapourise all of the substance at

temperature 12 is approximately twice the energy required to turn thesubstance from a solid at 0 'C to a liquid and then to raise its temperature toTz.C The specific heat capacity in the liquid state is higher than that in the solidstate.

D lf the substance is vapourised in a sealed container, it would require lessenergy to vapourise everything.5 An experiment is conducted to investigate the relationship between the volume yofa fixed mass of an ideal gas and its pressure p, while keeping its temperature

conslant.Which the graph shows the correct relationship at temperatures f7 and 12, whereTr > Tt?

c

\\ \..--_ i:-''--p

\


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Four charges of equal magnitude are arranged along the circumference of a circle.

li the magnitude of the electic field strength at the centre of the circle due to eachcharqe is E, what is the magnitude and direction of the resultant eleciric fieldsirength at the centre of the circle?

ABcD

J2 E towards the left\i 2 E downwards(."E - 1) r towaros the tett("E - t)e ao*n*aras

The equipotential lines of a positive charge are drawn as shown.12V --. oa.

Calculate the amount of work that has to be donepoint P to point Q (e is the elementary charge).

on an electron to move it to from

D 8e B -2e C +2e +8e


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The diagram shows how the electric potential energy of a charged particle variesalong a straight line within an electric field.

Electricpotentialenergy

Distance

At which point isminimum?

the magnitude of electric force acting on the charged particle aBBCCDD

The force of attraction between 2 unlike charges is 2.0 N. lf the distance betweenthem is increased to 3 times the original value, what is the force of attractionbetween them?

ABcD

0.22 N0.33 N0.44 N0.66 N


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10 Two conducting metal plates are placed parallel to one another as shown in thediagram. The potential ofone plate is +yand the other is +5y.

+V

+5VThe space bet\rveen the plates is divided equally by the dotted lines. P and Q are 2points that lie on the lines as shown- Determine the expression for the amount ofwork required to move a unit posiiive charge from pojnt P to point Q.

+4V

A wire P with resistivity, p, and length, /, has a resistance R. lf the wire is stretchedand its length is increased by 5% what would be the change in resistance of thewire? (Assume the volume of the wire has not changed.)

a4v B -2V +2V

A 104/. - 5v"

c D

D 100/0

11

5%

12 The diagram shows a circuit consisting of a cell, E, and a variable resistor, R.

lf the electromotive force of the cell is 10.0 V and the internal resistance of the cellis 2.00 O calculate the maximum power that is delivered to R.

5.00 w 125W 250W 50.0 w


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13

14

When 15.0 C of charge flows through a pariicular resistor 5.0 J of energy areconverted. What is the potential difference across the resistor?

0.33 V 30v 75V

6x1o3J 3.6 x 105 J

1 A towards Xll AtowardsX

20vAn electrical kettle requires 0.10 kwh of energy to bring its contents to a boil.Express this amount of energy in terms ofjoules.

15

0.028 J 0.36 J

The diagram below shows connected wires which carry cuffents of various values.What is the value and direction of the current / in shown in the diaoram?

Ac

I A away from X11 A away from X

ln the potentiometer above, a balancethe resistance wire XY is 1.0 m.

length of 0.70 m is obtained. The length of

BD

16

What is the resistance of XY?D

10 0 v

A 6.0 0 B 6.3 0 8.3 c) 10 ()


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17 An e.m.f. source E of internal resistance r, is connected to an external resistor ofresistance R. Which of the following graphs represents how the current, 1, throughthe external resistor, varies with the potential difference, y, across the resistor R?

'18 The circuit below consists of 10 identical resistors of resistance R.

What is the effective resistance across X and Y?2R c17 6 3R


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19 The graph above shows howtemperature f.

Rr/Q

the resistance Rr of the thermistor varies with

BO604.02.0

What is the20 "c?A 1.2 V

ABcD

potential difference y across the 8.0 O fixed resistor, when I isB 2.4V C 3.6V D 4.BV

20 A cuffent passing through a solenoid sets up a magnetic field around it. Which ofthe following will result in a stronger magnetic field strength within the solenoid?I increasing the current through the solenoidll using a shorter solenoid

lll inseriing a soft iron core into the solenoidland ll onlyland lll onlyll and lll onlyI, ll and lll


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A loop of flexible wire lies in a loose, irregular shape on the surface of a smoothhorizontal table. A uniform steady magnetic field of flux density I is directedvertrcally downwards tl^'ough the table.

to batiery

B into surface of tablelf the ends of the wire are connected to a battery such that there is a current in theloop in the direction shown, which oi the following is likely to be observed?

A The loop of wire moves vertically above the surface of the tableB The loop ofwire moves horizontaliy on the surface of the tablec The loop ofwire expands into a circle.D The loop ofwire collapses.22 A length of cuffent-carrying wire PQRST is placed in a region of uniform magnetic

field as shown in the diagram.

B field

Determine which segment of the wire experiences the greatest magnetic force

APO QR CRS ST


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23 A 2 kg mass is attached to a 5 kg massthrough a smooth pulley.

What is the value of x?

by a light inextensiblesmooth

strino which runsoullev

lf the slope on which the 2 kg mass lies is frictionless, determine the acceleration ofthe 2 masses.

25 Two stars of equal mass M move with constant speed v in a circular orbit of radiusR about their common centre of mass as shown in the diagram below.

Which of the following is th

1.40 m s-2 5.61 m s2 981 ms2

c

expresston tot v1IGM

B

24 When a force, F, varying as shown below, is applied to a mass of 10 kg, the gain inmomentum in 5 s is 40 kg m s-1.

F/N

time / s

1510

e correctFn!zn D


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Section BAnswer all questions

A fixed mass of monatomic ideal gas is made to undergo the processesbelow. The initial state of the gas is denoted by A where the gas4.0 x 105 Pa, volume of 7.5 x '10 3 m3 and a temperature of 450 K.

plPa40x'105-

shown in the tablehas a pressure of

Vc 7.5 x 10-3 x 1030.0(axi) Explain what is meanl by internal energy

AtoB Gas is allowed 10 expand isothermally until its volume is 10.0 x 'l O 3 m3.BtoC Gas is cooled at constant pressure to a temperature of 300 K.CtoD Gas is compressed isothermally lo a pressure of 4.0 x 105 Pa.DtoA Gas is allowed to expand at constanl pressure until it returns to its initial state at A.

.....111

For an ideal gas, explain why internal energy is dependent on its thermodynamictemperature only.

(ii)

I1l


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(bxi) Calculate the number of moles of ideal gas in the sample.

number of moles =

(ii) Using the ideal gas equation, or otherwise, determine pc and yc, the pressure and volumerespectively for the gas at C.

Pamt [3]

(iii) Calculate the work done on the gas during the process B to C.

I1l

(iv) calculate the change in infernal energy of the


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By considerinq the change in temperature,gas as it goes from siate B to siate C.

change in internalenergy = J I2I

(v) Hence, detennine the amount of heat which the gas exchanges wilh its surroundings duringlhe process from B to C. State clearly if heat flows into or out of the gas.

amount of heat exchanged = .................-......... Jdirection of heat flow = .............................. I2l

(c) For the overall cyclic process ABCDA, state if the net heat flow is into or out of the gas.Without making detailed calculations, explain your answer.

2 (al


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20v(D

(ii)

+40 v

(iv) Sketch, on Fig.2.2, the variation ofthe eleckic potenlialalong AB.

V 11]

loss in linelic energy =(;iD Determine the approxrmate value of the eleclric field strength ai C.

electric field strenqth =

J 12]

v m' [3]I2l

Eleclricpotential

Dislance

(b) An electron is released from rest at the position shown in Fig. 2.3. Two stationary protons


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are in the vicinity ofthe electron.

Fig.2.3(i) Describe the subsequent motion ofthe electron.

t2l

(ii) Determine the maximum kinetic energy which the electron attains during ils motion.Leave your answer in terms of e and r, where e is lhe elementary charge.

maximum kinetic energy= ..............................t31{iii) At the position where the electron has maximum KE, sketch the eleclric field pattern

due to the interaction of the 3 charges. 121

3 (a) Define the volf and use energy considerations to distinguish bet\reen electromotive force ot


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a cell and potential differerce behreen its terminals.

t3l

(b) A battery of e.m.f. 12.0 V and intemalresistance 7.50 Q as shown in Fig 3.'1.

resistance 0.50 O is connected to a resistor of

= 12.O V= 0.50 c)

BFig 3.1(i) Mark with an X, on Fig 3.1, the position of a switch so that the voltmeter may be used

to measure either the e.m.f. Eof thecell ortheterminal potential difference V. illDetermine(ii) the cuffent in the circuit,

R=7.50O

cUrrent = A [2] (iii) the potential difierence across the 7.50 O resistor,


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potenlial difference =

(iv) the potential at poinls A and B in the circuit,V 12]

potential at A =potential at B =

V 111v [1]

(v) the power supplied to the 7.50 O resistor.

power = .............................. w I21(c) Explain why the potential difference across the terminals of the cell is normally lower than

the cell's e.m.f. Under what condition is the potential difference across a cell's terminalsequalto its e.m.f.?

4(a) Fig. 4.1 shows a circuit containing a 10.0 V battery with a non negligible internal resistance


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r, and 6 external resistors.

Fig.4.1The potential differences across some ofthe resistors are given in Table 4.1 below.

Potential Difference / V

B 4Ac 3.0D

10

(D(i0

Table 4.1Conp ete -able 4.1 lo show ll.e polen|al difference across each lesislor. I3lWrite down the values of the electric potential at positions V and Y.

polential at V =potential at Y =

v t1lV 11]

(b) The potentiometer in Fiq. 4.2 consists of a non-ideal driver cell of e.m.f. 12.0 V with internal


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resistance of 2.5 O, a standard cell of e.m.f. E, and a 1-metre resistance wire XY. The totalresistance of XY is 8.0 O. Switch B is connected to part of lhe resistance wire at points Kand Y usinq connecting wires, such that length l(Y along the resistance wire is 20.0 cm.

Fig.4.2When Switch A is closed, and Switch B is opened, the balanced length is 60.0 cm,'1. What is the potential difference belween length XJ?

potential difference = V 12]

(i)

Calculate the e.m.f. E of the slandard cell.

200cm

Swilch A

(ii) B closed, Switch opened, calculate the new balanced


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When Swiich is and A islenqth.

(iii) With both Switch A and B both opened, state and explain one factor which canincrease the balanced length XJ.

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

t11

5 (a) A narrow beam of coherent light of wavelength 589 nm is normally incident on a diffraction


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grating with 5.00 x 105 lines per melre.(i) Find the total number of bright fringes that are visible on a screen placed at distance

number of bright fringes = ......................... . m [3](ii) Stale 2 ways 10 increase the number of brighl fringes observed on the screen.

...121

(b) Fig. 5.1 consists of a conducting rod XY which is placed on 2 horizontal parallel aluminiumrails AB and CD. The mass of rod XY is 12.0 g.

Fiq.5.1A uniform magnetic field of strength 0.200 T acts perpendicularly to the plane of the page,such thal when lhe switch is closed, rod XY moves to lhe left.

(i) State the direction of the current flow within rod XY when the switch is closed.direciion of current = Ill

(ii) State the direction ofthe uniform magnetic field-


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direction ofmagneticfield= ... . .. [1](iii) When the switch is closed, a current of 2.50 A flows in the circuit.

Calculate the magnetic force acting on rod XY if it has length 8.00 cm.

magnetic force = N 12](iv) To stop rod XY from moving to the left, the aluminium rails

equilibrium position where rod XY is stationary, draw lhe freeXY, indicating allthe forces acting on it.(Hint: draw the cross-section of rod XY.)

Determine the angle to the horizontal whichkeep rod XY stationary.

the aluminium rods must be tilted lo

can be lilted. At thisbodv diaqram of rod

I2l

(v)

angle to horizontal = ............................." t4l

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JC2 H2 Common Test