All IGCSE Physics Practicals 2015

7/25/2019 All IGCSE Physics Practicals 2015

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IGCSE Physics Practicals 2015


2/79

Practical 100 NAME ______________________________________________________

Macleans College

IGCSE Physics Practical

Measuring-Part 1 and Part 2

Gear:

PART 1-blocks of various shapes and sizes,micrometer,calipers

PART 2 -stopwatch, 60 glass slides, micrometer, calipers, electronic scales, string, meter ruler,

pendulum

Instructions

Record your data in a suitable table

Choose one of the blocks and sketch its shape (spend no more than 1 minute to do this)

Label each length, width and height; l, w and h

Measure each length with your ruler, caliper and micrometer

Calculate the volume and surface area of the block. Show your calculations.

Formulae

a = l2 area of a square = length of side squared

a = l w area of a rectangle = length x width

a = bh area of a triangle = x base x height

a = r2 area of a circle = x radius squared

v = l3 volume of cube = length of side cubed

v = lwh volume of cuboid = length x width x height

v = r2h volume of cylinder = x radius squared x height

PART 2Instructions

Use the appropriate instrument or method to measure the following and explain why;

1. the length of your homework diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. the width of your homework diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. the thickness of your student ID card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. the radius of your pen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. length of string that has been wrapped 10 times around your pen . . . . . . . . . . . . . . . . . . . . . . .

6. the thickness of a glass slide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.

the period of oscillation for a 25cm length pendulum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=502.0http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=502.0http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=502.0http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=52http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=52http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=52http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=52http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=502.0


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Practical 102 NAME ______________________________________________________

Macleans CollegeIGCSE Physics Practical

Number of Oscillations of a Simple Pendulum

Gear: simple pendulum, retort stand, boss head, clamp, cork with slit, metre ruler, stopwatch

Instructions

1. Set up the gear as shown use a length of about 30 cm.

2. Record it. ______________________________________

3. Hold the bob about 5cm from vertical. Start the timer when you

release the bob at position a.

4. Stop the timer when it returns to the same point.

This is one oscillation. Record this as t and n = 1.

5. Repeat for n =2 (the bob makes two oscillations)

One oscillation occurs when the bob moves from a to b to c and back to a.

6.

Repeat for other numbers of oscillations.7. Complete a table as shown;

N (number of oscillations) t- time (s)

1

2

3

5

8

11

14

Plot a graph of t (vertical axis) against n (horizontal axis). Plot a cross x at each point

Draw a line of best fit (best guess)

Use your graph to estimate the time for 10 oscillations

The length should be

taken from the pivot

point to the centre of

mass of the bob


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Practical 102 NAME ______________________________________________________

1. How does the number of oscillations compare with the time taken?

2.

Is there a pattern?

3. Is there a formula you could write to relate N and t?

4. Can you use the formula to determine how many oscillations would occur if T = 20 s?

5. Can you use the formula to determine T for 30 oscillations (if possible)?


5/79

Practical 104 NAME ______________________________________________________

Macleans College


Oscillations of a Simple Pendulum

Gear: simple pendulum, retort stand, boss head, clamp, cork with slit, metre ruler,

stopwatch

In this investigation you are to record the period of oscillation of a simple pendulum.

One oscillation occurs when a pendulum bob moves from a through b to c and then back to

a. The time this takes is called a period

Instructions

1. Read through these instructions before you begin

1. Set up the gear shown.

2. Set the length of the pendulum to 0.40 m

3. Record 10 oscillations in your table.

4. Calculate T, the period of one oscillation.

5. Repeat for a length of 0.25m

6. Repeat the above using different lengths and record the data on a table as shown

Length of

pendulum (m)

Time for 10

oscillations (s)

Time for one

oscillations(s)

0.25

0.40


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Practical 104 NAME ______________________________________________________

7. Draw a graph of Time for one oscillations(s) vertical axis against Length

8. Plot the points accurately with a small x for each point on the axes below

9. Draw a simple smooth curve to match the points. your curve does notneed to touch

any points but an accurate data would)

10.Does your graph suggest that the time for an oscillation is proportional to the

length?

11. What you did to make your results as accurate as possible

LO

Measure and describe how to measure a short interval of timeUsing graph skills

Length (m)

Time for one

oscillations


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Practical 106 NAME ______________________________________________________


Density

Gear: metal cubes, glass slides, electronic balance, 100 mL measuring cylinder, small items(eg fishing sinkers or stainless steel nuts that fit into measuring cylinder), water, rags, beakers

metal density (kg m-3)aluminium 2700

titanium 4500

zinc 7135

iron 7850

brass 8500

copper 8930

lead 11340

uranium 18900

gold 19320

tungsten 19600

InstructionsCopy and complete the table

1. Measure the length, width and thickness of a glass slide.2. Weigh the mass of glass slide with electronic balance (in g)3. Calculate the density of the glass slide. Use 1000 kg m-3= 1g cm-34. Determine the density of the metal cubes. Can you identify them?5. Explain how you would use a measuring cylinder to determine the density of an

irregularly shaped object.

Object length/mm width/mm thickness/mm mass/g volume /cm-3density

/g cm-3


8/79

Practical 106 NAME ______________________________________________________

LO

*Describe an experiment to determine the density of a liquid and of a regularly shaped solid

and make the necessary calculation

*Describe the determination of the density of an irregularly shaped solid by the method of

displacement, and make the necessary calculation* use Density = mass / volume


9/79

Practical 200 NAME ______________________________________________________


Describing motion

Gear ticker timer, ticker tape, power supply

Each student needs 4 x 25cm lengths of ticker tape

Produce dots on the tape that show (i) steady speed (ii) higher steady speed (iii)

increasing speed (iv) increasing then decreasing speed

Glue these tapes into your books and label them.

For each tape plot a distance-time graph for the first 20 dots (0.0s 0.40s).

Either; use a different colour for each tape or new graph paper

ExtensionProduce speed time graphs for your tapes


10/79

Practical 202 NAME ____________________________________________________


Calculating Average Speed

Gear: trolley, ramp, metre ruler, stopwatch

Aim To calculate average speed

1.

Release a trolley from rest

2. Observe the motion. trolley

3. Assume its speed at the end of the ramp is v final

4. Think of a way to determine its average speed v ave

5. Write your method so that another y11 student can follow your instructions

6. Try it.

7. Write your results and explain how the average speed is related to the final speed.

Questions

A trolley is released from rest at the top end of a 1.8 m track. It has a final speed of 3.6 m/s at

the lower end of the track.

Qu 1 What was its speed at 0.9 m from the top end of the track?

Qu 2 What was the time of travel?

Qu 3 What assumption has been made to answer the above questions?


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Practical 204 NAME ______________________________________________________


Distance along a ramp

Gear: 1.2 m length ramp, block (10cm), trolley, stopwatch, 1m ruler

Instructions

7.

Set the gear as shown in the diagram

8. Place the trolley at the top of the ramp. Determine its position on the ramp. ___________

9.

Time the trolley to travel 0.2 m down the ramp.

10.Record in a table as shown

Distance travelled / m Time /s Acceleration / m s-2

0.2

0.5

0.7

0.9

1.01.1

11.

Repeat for increasing distances as indicated by the table above.

12.Calculate its acceleration using : a = 2 x distance travelled divided by time squared

7.

Plot a graph of distance travelled

(vertical axis) against time on these

axes

8.

Draw a single smooth curve9. What conclusion can you make

regarding the motion of a trolley

down a gentle slope?

10.

What would be the shape of the

speed-time graph of this

arrangement?


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Practical 205 NAME ______________________________________________________


Measuring Acceleration

Gear: trolley, 1.2 ramp, ticker timer, 12 V a.c. supply, 1m ticker-tape, sticky tape, scissors

Aim To analyse acceleration using a ticker timer.

The ticker timer produces exactly 50

dots each second. Therefore the time

to make two adjacent dots is 0.02 s.

From the spacing of the dots, you

can work out the acceleration of the

trolley. The diagram shows a length

of ticker-tape fixed to a trolley. As

the trolley rolls down the ramp it

pulls the ticker tape.

1 Set up the apparatus as in the diagram. Use 12V ac.

2 Switch on the ticker timer and adjust the wing nut if the hammer does not

work. Release the trolley (You may need to try different angles).

3 Remove the tape and cut it into sections 10 dot-spaces long. Stick these

side by side in your book/ page.

4 The length of each section of tape shows the distance travelled by thetrolley in 0.2 s (see diagram). Choose a slow section of tape and

measure its length. Work out the average speed of the trolley over that

section using this equation:

average speed length of section (m)

(m/s) time (s)

5 Choose a fast section of tape. Use the above equation again to work out the average

speed over this section.

6

Work out the time between your slow and fast sections. It is 0.2 seconds for everysection. So this example shows 0.8 seconds.

7 Calculate the acceleration of the trolley using this equation:

acceleration fast speed slow speed (m)

(m/s2) time between sections (s)

Do either 8 or 98 Repeat with the ramp angle 2-5osteeper.

9 Describe and sketch a distance time graph if the acceleration was 1 m s-2

=

=


13/79

Practical 206 NAME ______________________________________________________

mass


Acceleration due to gravity

Gear: ticker timer, 12 V a.c. supply, 0.60 m ticker-tape (for each student), sticky tape, 50 g mass

Instructions

1. Set the gear as shown in the diagram (the ticker timer is about0.5 m above the ground).

2.

Do a trial run to see if the tape runs smoothly through the ticker timer.

3.

Only when the mass is at the highest position and the tape is not twisted and clear of the gaps then turn on

the ticker timer. Then release the mass.

4. Repeat until each student has their own ticker tape to analyse

i.

Mark the first clearest dot and label it 0.0s

ii. Mark every 5th

dot and label them 0.1s 0.2s 0.3s etc. (ignore rebounds or double marks)

iii.

Measure the distance, between each mark (in metre)

iv.

Calculate the average speed between marks using distance / 0.1 seconds

Distance travelled

between marks/ m

Time /sAverage speed/ m s

-1

0.0

0.1

0.2

0.3

0.4

0.5

0.6

tapeticker timer


14/79

Practical 206 NAME ______________________________________________________

v. Plot average speed (vertical axis) against time (be neat, tidy, accurate)

vi. Draw a line of best fit (best estimate of a line that passes through maximum number of points with minimum

spread)

vii.

Determine its gradient (use rise over run and include units)

viii.

What does the gradient mean? What is its unit?


15/79

Practical 207 NAME ______________________________________________________


Finding acceleration from a ticker tape

Gear: trolley, 1.2 ramp, ticker timer, 12 V a.c. supply, 0.5 m ticker-tape, tape

Aim To determine acceleration using a ticker timer.

1. Mark the first clearest dot (start).

2. Label it 0.0s

3. Mark every 5th dot until end of the tape.

4. Label each mark (0.1s, 0.2s)

5. Enter time in column 1

6.

Calculate the distance between each mark and enter into column 2.7. Calculate average speed between marks ( v = (d2-d1)/0.1 =) and enter into column 3

8. Calculate the acceleration ( a = (v2-v1)/0.1 )and enter into column 4

Time

(s)

Distance between marks (m)

d = d2 d1etc

Average speed between

marks (m/s)ave v = d/ 0.1

Acceleration (m/s/s)

a = (v2-v1)/0.1

0.0

0.1

0.2

0.30.4

0.5

0.6

Write a conclusion (based on your data)


16/79

Practical 207 NAME ______________________________________________________

EXAMPLE

Time

(s)

Distance between marks (m)

d = d2 d1etc

Average speed between

marks (m/s)

Ave v = d/ 0.1

Acceleration (m/s/s)

a = (v2-v1)/0.1

0.00.1 0.009 0.09 1.3

0.2 0.022 0.22 0.9

0.3 0.031 0.31 1.2

0.4 0.043 0.43 1.0

0.5 0.053 0.53 1.3

0.6 0.067 0.67

In this example the acceleration fluctuates between 0.9 and 1.3 m/s/s ie approx. 1.1 m/s/s

Calculate your acceleration (and uncertainty) from your data


17/79

Practical 208 NAME ______________________________________________________


Measuring g (the acceleration due to gravity)

Gear: steel ball bearing free fall adaptor and Pasco photo gate timer

Instructions

1.

Read through these instructions before you begin

2. Set up a retort and clamp on a table to hold the free fall adapter

Release clamp

Height Pasco photo gate timer

Pressure sensor pad

3.

Practice dropping the ball bearing from the clamp so it hits the sensor pad every time

4. When you are ready then turn on the timer (check it reads zero)

5. Release the ball

6. Record the time and the height

7. Repeat and average

8. Use your average time in the equation s = ut + at2

u = initial speed = zero

9.

Try three different heights

10.Make a conclusion


18/79

Practical 212

Practical 209 NAME ______________________________________________________

Macleans College


Terminal velocity

Gear: 2 x 1 meter rulers, stopwatch, A4 paper, paper clips, sticky tape

Instructions

1. Read through these instructions before you begin

2. Construct a suitable table for all of your results

3. Measure 2.000 m height.

4. Drop a sheet of A4 paper from the height and record the time to reach the ground

5. Repeat this three times and average the results

6.

Fold the paper in half and repeat the measurements

7. Fold again and repeat

8.

Continue until you are no longer able to fold the paper (or upto 7 folds)

9. Repeat step 4 and 5 with a paper clip taped to the centre of the sheet

10.

Repeat step 10 with the paper completely folded so it has very little surface

11.In each trial release the sheet parallel to the ground (where possible).

12.Write a conclusion for this experiment.

Extension

Either

Design a sheet of A4 paper to maximize the time for the paperclip to reach the ground

Explain how these images relate to this practical

1.

Read through these instructions before you begin

2. Construct a suitable table for all of your results

3.

Tape a paper clip near the center of an A4 sheet4. Hold the sheet horizontally 2.000 m above the ground

5. Drop it and time it to reach the floor

6. Repeat this three times and average the results

7. Fold the paper in half and repeat the measurements (leave the

paper clip on the outside)

8. Continue until you are no longer able to fold the paper (or upto 7 folds)

9.

Plot Size of paper horizontal axis vs time

10.Explain in terms of forces why this pattern occurs

A ball falls from a very high position from rest and reaches terminal velocity.

1. Describe its motion as it reaches terminal velocity

2. Explain how terminal velocity occurs in the ball.


19/79

Practical 212

Jumbled sentences

SORT THESE SENTENCES INTO TWO PARAGRAPHS TO ANSWER THE QUESTIONS

Some of the sentences are wrong and must be discarded

1) At terminal velocity friction is balanced by the weight of the object.

2)

Initially the acceleration is 9.8m/s/s.

3)

Initially the friction is much much smaller than the weight so acceleration is high4) Initially the speed increases at a decreasing rate.

5) It eventually reaches terminal velocity which is its maximum speed.

6) Since friction is proportional to speed the friction grows and eventually it balances the weight

7) So the forces are no longer unbalanced

8) So unbalanced force = 0.

9) Terminal velocity is independent of the shape of the object

10)The acceleration drops to 0 when it is travelling at terminal velocity.

11)

The speed remains constant throughout the whole journey

12)This occurs due to friction (this force is due to drag or air resistance)

velocity velocity

Time timeWithout air resistance with air resistance

The speed increases at a decreasing rate.

It eventually reaches terminal velocity which is its maximum speed.

Initially the acceleration is 9.8m/s/s.

Initially the friction is much much smaller than the weight so acceleration is high

The acceleration drops to 0 when it is travelling at terminal velocity.

This occurs due to friction (this force is due to drag or air resistance)


20/79

Practical 212

Since friction is proportional to speed the friction grows and eventually it balances the weight

So the forces are no longer unbalanced

So unbalanced force = 0.

At terminal velocity friction is balanced by the weight of the object.

For a human terminal velocity is about 50 m/s

With a parachute this may be reduced to about 5 m/s

Link
http://hypertextbook.com/facts/JianHuang.shtmlhttp://hypertextbook.com/facts/JianHuang.shtmlhttp://hypertextbook.com/facts/JianHuang.shtml


21/79

Practical 220 NAME ______________________________________________________

Macleans College


f=ma

Equipment: Trolley, pulley, string, 20 g slotted masses, stopwatch

Instructions

1. Set up the gear as shown below

2. Measure the height, h, of the 20g mass above the floor (in metres)

3. Time the mass to reach the floor (and pull the trolley from rest)

4. Use a=2h/t2to work out the acceleration in ms-2

Mass (kg) Weight (N) height (m) Acceleration ms-2

0.02 0.2

0.04 0.4

0.060.08

0.10

0.12

10.

Plot a graph of weight (vertical axis) against acceleration

trolley

pulley

mass

bench


22/79

Practical 220 NAME ______________________________________________________

11.What can you conclude about the weight and acceleration of the trolley?

12.Explain how we could improve this experiment

LOPlot extension/load graphs and describe the associated experimental procedure

Weight

(N)

0.0

Acceleration (ms-2

)


23/79

Practical 221 NAME ______________________________________________________

Macleans College


A = f/m

Equipment: Trolley, pulley, string, 20 g slotted masses, 5x50 g slotted masses, stopwatch,

electronic balance

Instructions

1. Set up the gear as shown below

2. Calculate the total moving mass ( trolley, all slotted masses and the 20g mass)

3. Measure the height, h, of the 20g mass above the floor (in metres)

4. Time the mass to reach the floor (and pull the trolley from rest)

5. Use a=2h/t2to work out the acceleration in ms-2

6. Write your results in the table

7. Remove a 50g mass from the trolley and repeat the above

8. Continue until after all 50g are removed

Total moving mass (kg) Weight (N) height (m) Time (s) Acceleration ms-2

10.Plot a graph of acceleration (vertical axis) against total moving mass

trolley

pulley

20 g mass

bench

50 g masses


24/79

Practical 221 NAME ______________________________________________________

11.What can you conclude about the total moving mass and acceleration of the trolley?

12.Explain how we could improve this experiment

LOPlot extension/load graphs and describe the associated experimental procedure

Acceleration

(ms-2

)

0.0

total moving mass (kg)


25/79

Practical 240 NAME ______________________________________________________

Macleans College


Hookes law

Equipment: clamp, retort, spring, metre ruler, 50 g slotted masses

Instructions

1.

Set up a retort stand with a clamp

2. Suspend one end of the spring to the clamp

3. Attach a 50 g base weight to the other end.

4. Record the position of the base in a table as shown

5. Complete the table below

6. Calculate Load ( = mass x 10 )

7. Calculate Extension (= new position original position )

Mass (kg) Position (m) Load (N) Extension(m)

0.05 0.5 0

0.15

0.20

0.35

0.40

0.50

10.Plot a graph of extension (vertical axis) against load

extension

(m)

spring

weight

0.0 1.0 2.0 3.0 4.0 5.0 load (N)


26/79

Practical 240 NAME ______________________________________________________

11.What can you conclude about the load and extension of the spring?

12.Predict the extension if a load of 2.5N was used.

13.Predict the load required to give an extension of 0.095m

14.

Predict the mass required to give an extension of 0.115m

15.Describe Hookes Law 3.03

16.

Does a limit of proportionality exist for this spring?

17.Explain your answer

Duplicate graph if required

LO

Plot extension/load graphs and describe the associated experimental procedure

extension

(m)


27/79

Practical 248 NAME ______________________________________________________

Macleans College


Equilibrium 1

Equipment: metre ruler, 50 g masses, pivot (thin card, two wooden blocks), electronic

balance, objects to weight (eg keys, pencil case, metal cubes (large), wooden block to supportlarger objects

Instructions

1. Make up a table to enter your data

2. Balance the ruler on the pivot over the 50.0 cm mark (approx.)

(if necessary move the ruler until it balances or add tape at one end)

3. Place the 50 g mass at the 30.0 cm mark

4. Place your object on the rule and slide it left or right until it balances

5. Measure the length Y

6.

Use the relationship m1d1= m2d2to determine the mass of the object

7.

Measure objects with an electronic balance

8.

Determine the percentage error using 100% x mass from calculation / mass frombalance

9. Repeat for 5 other items (eg pencil, scissors)

LO

Demonstrate understanding that weights (or masses) may be compared using a balance

Tabulating results


28/79

Practical 249

Macleans College


Equilibrium 2

Equipment: metre ruler, 50 g slotted masses, pivot (thin card, two wooden blocks)

Instructions

1. Read through these instructions before you begin2. Balance the ruler on the pivot over the 50.0 cm mark (approx.)3. (if necessary move the ruler until it balances or add tape at one end)4. Place the 150 g mass at the 30.0 cm mark5. Place the 100 g mass at the 60.0 cm mark6. Place the 50 g mass on the ruler so they all balance7. Record the results in a table as shown

Position of pivot = 50.0cm ACW = anti clockwise CW = clockwise

Position of Distance from pivot Moment about pivotTotal moment

150g 100g 50g 150g 100g 50g 150g 100g 50g30cm 60cm ? 10cm 10cm ? 3000 gcm

ACW

1000 gcm

CW

? zero

8. Repeat for 4 other balanced situations (vary position and/or mass)9. Draw a force diagram of one of your situations and show the calculation for the net

moments about the pivot point (ref p50)

EXTENSION

Build a balanced toy and take a photo of it

LO

Perform and describe an experiment (involving vertical forces) to show that there is no netmoment on a body in equilibrium


29/79

Practical 260 NAME ______________________________________________________

Macleans College


Locating the Centre of gravity

Gear: card, scissors, pin or nail, plumb line

Aim: to determine the position of the centre of mass of a plane lamina (or card)

Instructions

1) Cut out a shape on cardboard so that it has an area of about half a page

2) Make a holenear the edge of the card

3) Put the pin or nail through the hole so the card freely hangs from it

4) Hold a plumb line next to the hole.

5)

Trace the vertical line on to the card.6) Use a ruler to mark the line clearly

7) Make another hole in a different part of the card (try rotating 120o)

8) Repeat and obtain a different line on your card

9) Find their intersection this should be its cog

10)Repeat with a third hole

11)If you have been working carefully, this line should pass through the same point as the other two.

12)

To check your result, hold the card horizontal on your fingertip.13)If your finger is directly below your cog then the card should balance.

14)Explain why the card balances at the cog

LO

Perform and describe an experiment to determine the position of the centre of mass of a plane lamina


30/79

Practical 280 NAME ______________________________________________________


Explain the Toy

Gear: variety of toys, stopwatch, ruler, tape, 10g masses

Instructions

Choose a toy. Observe how it is used.

Spend a few minutes thinking about the energy used and produced.

For example Does it use elastic energy? If so where and what does it do? Where did it

originate? Was gravity needed? How many energy conversions were involved? What would

be needed to make the toy work better?

Prepare a 3-5 minute speech to explain the physics of the toy

Test your ideas by altering some parameters (not permanent)

-for instance tape 0.5 g mass to its side

- increase the slope of the ramp slightly

-change the surface material (carpet instead of table top)


31/79

Practical 282 NAME ______________________________________________________

Macleans College


Loop the loop track & marble

Gear: track, marbles, ruler

Instructions

1.

Place the marble at the top of the track and release. It should roll and complete thetrack. Repeat at a slightly lower starting height. Continue until the ball cannot finish

the whole length of the track. What is the minimum heightfor which the ball finishes

the track without leaving it? Try different marbles. Is the size important?

2. Give several reasons why the ball does not finish the track.

EXTENSION

3. Determine a relationship between the radius of the circle and the minimum height

for which the ball can complete the track

marble


32/79

Practical 284 NAME ______________________________________________________


Newtons Cradle

Gear: Newtons Cradle, ruler

Instructions

1.

Pull one ball back a few centimeters and release to strike the stationary set of balls.

Observe the first bounce only.

2. How many balls continued in the same direction?

3. Did it (they) rise to the same original height?

4. Measure and record both heights.

5.

Try with different number of balls.6. How do the heights compare?

7.

Did the same number of balls leave compared to the original number of balls that

struck the stationary set?

8.

Was there any occasion where a different number left the set?

9. Can you think of a reason why (e.g. if two balls strike a set why doesnt one leave)?

10.

What would happen if the balls were made of putty instead of steel?

Animation
http://www.lhup.edu/~dsimanek/scenario/newton.htmhttp://www.lhup.edu/~dsimanek/scenario/newton.htmhttp://www.lhup.edu/~dsimanek/scenario/newton.htm


33/79

Practical 300 NAME ______________________________________________________

Macleans College


Hot and Cold

Gear: 2 x 250mL beakers stirring rod thermometer

Instructions

Record the temperature of 20 mL tap water

Record the temperature of 20mL warm water

Predict the temperature when they combine.

Try it.

Can you explain the result?


34/79

Practical 310 NAME ______________________________________________________


Thermometers & Ice

Aim: to observe temperature changes

Gear: Thermometer, ice, jug, stopwatch,

Instructions

1.

Place a thermometer in an empty beaker

2. Record the temperature every 15 s for 6 minutes

3.

After 60s put the bulb on a cube of ice

4. After 120s the bulb on a cube of ice

5.

Add 20mL tap water to the ice and continue recording every 15 s for 2 minutes6. Add 20 ml hot water continue recording undisturbed every 15 s for 2 minutes


35/79

Practical 330 NAME ______________________________________________________


SPECIFIC HEAT CAPACITY OF WATER

Gear: ammeter, power pack, stop watch, thermometer, polystyrene cup, polystyrene lid, measuring cylinder

and nichrome wire heating coil.

Aim: to find the specific heat capacity of water.

Specific heat capacity of water is the amount of energy required to raise the temperature of 1kg of water by

a degree Celsius

What to do:1. Set up the equipment as shown below

2. Measure 50ml of water and pour it in the polystyrene cup.

3. Measure and record the initial temperature of the water.

4. Set the power supply voltage to 12 V DC.

5.

Switch on the circuit and start the stop watch concurrently.

6.

Record the ammeter reading

7.

Switch off the power supply after 5 minutes, stir and record the water temperature.

Results and analysis

Draw a suitable table to record all the results

Calculate the heat energy dissipated by the nichrome coil in 5 minutes

How much heat energy is gained by water

Calculate the specific heat capacity of water.

Discussion

Find the official value for the specific heat capacity of water and compare it with yourcalculated value.

List the ways in which the accuracy of the calculated value for the specific heat capacity can

be improved.


36/79

Practical 350 NAME ______________________________________________________

Macleans College


Determining the latent heat of fusion of ice

Gear: 100mL measuring cylinder; 250mL beaker, scales, thermometer, ice cube, stopwatch

1. Measure the temperature of 100 mL water in a 250 mL beaker (or calorimeter)

2. Determine the mass of an ice cube (weigh on electronic balance)

3. Put the ice cube into the water and stir it until it completely disappears

(stir with a stirring rod not the thermometer)

4. Re-measure the temperature

5. Calculate

T the difference in the temperatures

We know that c = 4200, m = 0.1 kg (= 100 mL)

6. Use H = mcT to determine the heat gained by the ice.

7. Use H = mL to determine L (the latent heat of fusion of ice)

0.01


37/79

Practical 400

Macleans College


Sound and the oscilloscope

Gear: signal generator oscilloscope, microphone, connecter, tuning fork set, large speaker

cone (with out the box covering), connecting wires, alligator clips, balloon

Aim

To observe sound waves and some of their effects

Instructions

Connect the signal generator to the oscilloscope and speaker. Observe the wave forms

produced by different electrical signals and compare them to the sound that you hear.

1.

List two ways that the electrical signal and sound are similar2. List two ways that the electrical signal and sound are different

Connect the microphone to the oscilloscope and observe the wave forms produced by each

sound. These questions refer to the pattern seen on the oscilloscope screen

3. How are loud sounds different from quiet sounds?

4. Which objects produce simple repetitive waves?

5. Draw a sound wave produced by a tuning fork of low frequency.

6. Draw a sound wave produced by a different tuning fork with a higher frequency.

7. What diagrammatical feature have you drawn to show that the two waves are different?

8.

How do the waves that you have drawn differ from a real sound wave?

The Oscilloscope

This is a useful device to measure the frequency and

voltage of an electrical signal. A spot sweeps from left to

right across the screen. A 1 V signal makes the spot move

up one 1V. This is found by the amplitude x gain. The

frequency can be found from the wavelength x timebase.

The gainis the number of squares from the middle of the

wave to the top.The timebaseis the time for the spot to move right one

square.

In this example the time base is 10 ms (per square) and the gain is 2 V

This signal then represents a peak voltage of 2.3 (squares) x 2 V = 4.6V and a period of 10

(squares) x 10 ms = 100 ms. Since f = 1/T then f = 1 / 0.1 s = 10 Hz

Set the timebase to 10 ms on the oscilloscope and set the frequency of the signal generator to

100 Hz. Accurately draw the wave on a grid (your graph paper will do) and state important

features.


38/79

Practical 410 NAME________________________________________________________

Macleans College


Types of wave

Gear: thin long slinky, wide slinky, stop watch, metre rule

AimTo observe two different types of waves

Instructions

Make clear labelled diagrams in your practical books

1. Hold one end of a thin slinky on the ground. Have your partner hold the other end on

the ground. Stretch it about 1 m.

2. Wobble your end perpendicular to the slinky and horizontal with the ground. Make the

frequency about 1 Hz.

3.

Observe the slinky just beforethe wave reaches your partners hand.

4. Draw this pattern and show two or three waves.

5. Repeat with a slightly higher frequency it is important to get the same length of the

slinky.

6.

Repeat both several times so that you get an accurate measurement of the wavelengths.

7. Show the measurements of the wavelengths clearly on your diagram.

8. Repeat the above and show the wave after the reflection off your partners hand.

9. Repeat the above and use a stopwatch to determine the period of ten oscillations then

from this determine the frequency.

10. Repeat for the higher frequency.

11.

Repeat all of the above using the wide slinky except push it forwards and backwards

instead of side to side motions.

ExtensionDetermine the speed of the waves from the information that you have drawn and labelled.

Research: What is the speed of sound in air and water?


39/79

Practical 450 NAME ______________________________________________________

x

Macleans College


Reflection

Gear: flat mirror, paper, drawing pin board, 2 optical pins, ruler

Aim: to determine the position of an image in a flat mirror

If you put a pin in front of a

flat mirror, you see an

image in the mirror. The

image appears to be behind

the mirror. To find its

position, you have to

point lines at it from two

different directions and

find out where they meet.

Instructions

1)

Put your paper on the drawing pin board.

2) Stand the mirror upright in the middle of the paper.

3)

Draw a line along the front of the mirror with a pencil.

4) Insert a pin upright about 10 cm in front of the mirror, x

5)

Mark its position on your paper.

6) Put the ruler on your paper -near position A.

7) Rotate your ruler until its edge lines up with the image of the pin (you will see the

edge of the ruler in line with the image).8) Draw a line along the edge of the ruler (line A).

9) Move the rule to position B.

10)Again, move it until one edge lines

up with the image of the pin.

11)

Draw a line along the edge (line B).

12)Remove the pin and mirror from the

paper.

13)Extend the two lines until they cross.

This is where the image seems to be.

14) Label this point I.

Check your results:

1) Draw a line from X to I and measure halfway.

2) This is where the mirror should be. Measure the difference.

3) Put the mirror and the pin back into their original positions. Hold a second pin

upright behind the mirror at the point where your two lines cross. Look into the

mirror. You should see the top half of this second pin exactly in line with the image

of the first pin. The pin should stay in line with the image even when you move your

head from side to side.

4)

How accurate were your measurements?


40/79

Practical 455 NAME ______________________________________________________

Macleans College


Multiple Reflections

Gear: two flat mirrors, paper, protractor, optical pin, ruler

Aim: to determine the equation that relates the number of images, n, with the angle,

between two flat mirrors

Instructions

1) On a flat sheet of paper mark a mirror line X-Y

2) Mark 5 lines from X so that they form different angles ;22.5o,45o,60o72oand 90o

3) Use the 90olines and put two mirrors on them (they should face each other)

4) Mark an x on the sheet between the mirrors and put the optical pin there.

5)

Can you see all three images when you look in any mirror (keep mirrors vertical)?6) Change the angle and recount the number of images you observe.

7)

Continue using other angles

8)

Can you make an equation that relates n and ?

9) What would happen if the mirrors were parallel and facing each other?

X X


41/79

Practical 460

Macleans College


Tracing light rays through a perspex block

Gear: power pack,ray box, perspex rectangular block, single slit, protractor

Aim: to observe the path of light in a transparent rectangular block

Instructions

1 Place the block in the middle of

the paper. Draw round the block

to mark its position.

2 Point the ray-box (with a thin

beam of light) into the block.

3 Angle the ray so that it goes in and

out of the block as in the diagram.

4 Using a pencil, mark the path of

the ray going into the block. Two

small crosses are good for this

drawn as far apart as possible.

Then mark the path of the ray

leaving the block.

5 Take the block and the ray box

away. Using your crosses as a

guide, draw in lines to show the

path of the ray as it enters and

leaves the block. Join up the lines

to show the path of the ray inside the block.

6 Measure the angle of incidence of the ray entering the

block (angle i in the diagram). Then measure the

distance between the paths of the rays entering andleaving the block (distance din the diagram).

7 Repeat for at least six values of iand put your results

in a table.

8 Plot a graph of dagainst i. Can you draw any

conclusions from the graph?


42/79

Practical 460

d/cm theta(degree) sin (theta) d/cm

0.8 21 0.3583 0.81.0 28 0.4694 1.0

1.4 38 0.6156 1.4

1.8 47 0.7313 1.8

2.6 57 0.8386 2.6


43/79

Practical 10a

Practical 465 NAME ______________________________________________________

Refractive index of a semi-circular block

Gear:power pack,

ray box, glass semi-circular block, single slit, protractor, graph paper

Aim: to determine the refractive index of

perspex

Instructions

1 Place the block in the middle of the paper.

Trace around its edge.

2 Measure the diameter and mark the centre

with an A

3 Shine a single ray of light at A

4 Mark the point where it emerges from theblock (label)

5 Repeat for 5 different angles

6 Remove the block and draw each ray.

7 Draw the normal

8 Measure i and r for each (write in

9 Calculate sin i and sin r

10 Plot sin i (vertical axis) against sin r

11 Write a conclusion


44/79

Practical 10a

Practical 467 NAME ______________________________________________________

Macleans College


Refractive index of a glass-block

Gear: power pack,ray box, perspex rectangular block, single slit, protractor, graph paper

Aim: to determine the refractive index of a glass rectangular block

Instructions

Copy and complete a table such as this

Angle of

incidence

Angle of

refraction

Sin i Sin r

10

25

30

40

45

60

75

85

1 Place the block in the middle of the

paper. Trace around its edge.

2 Point a thin beam of light into the block

(angle of incidence = 30o)

3 Mark the entry point A

4 Mark the point where it emerges from

the block (label it 30o) B

5 Repeat for different angles (10, 25, 40,

45, 60, 75, 85) but always use entry

point A6 Remove the block and draw each

refracted ray.

7 Measure the angle of each refracted ray

8 Determine sin i and sin r

9 Plot sin i (vertical axis) against sin r

10 Calculate the gradient

11 What does this gradient tell us?

12 Write a conclusion

A


45/79

Practical 470 NAME ______________________________________________________

Macleans College


Total Internal Reflection

Gear: power pack,Light box single slit Glass blocks (perspex scatter too much light),

Students needprotractor and paper

Aim: to observe total internal reflection by reflection in transparent blocks

In this experiment, you pass a ray of light in and out of a right-angled prism so that it reflects

off an inside face.

Instructions

1

Place the prism in the middle of the

page. Draw round the prism to mark

its position.

2 Set up the ray box as shown. Make

the ray strike one of the short faces of

the prism square on as in diagram A.

How can you do this accurately?

3 Mark the path of the ray going into theprism. Mark the path of the ray

leaving the prism. Then mark the

point where the ray reflects from the inside face of the prism.

4 Remove the prism and the ray box. Draw in the path of the ray going into, through and

out of the prism.

In this part of the experiment, you change the path of the ray so

that it reflects off two inside faces.

5 Repeat the steps above only this time make the ray meet

the prism as in diagram B.

6 When light reflects from a mirror, the angle of reflection is

equal to the angle of incidence (see diagram C). Is this law

also true for light reflected from the inside face of a prism?Use your ray-tracing experiments to find out.


46/79

Practical 475 NAME ______________________________________________________

Macleans College


Critical Angle

Gear: power pack,light box (ray box, single slit), semi circular glass block, semi circular(hollow plastic) dish with water. Students need their protractor.

Aim:to measure the critical angleof perspex

If a ray of light meets the inside face of a glass

block as in the top diagram, some of the light is

reflected and some is refracted. Increase the

angle of incidence and eventually the refracted

ray will disappear (90oto the normal) as in the

diagram below.

The angle

shown is called the critical angle. At greater angles

than this, there is no refracted ray. All the light is

reflected.

In this experiment, you will measure the critical

angle of glass, perspex and (possibly) water.

Instructions

1.

Place the block in the middle of the paper. Draw round the block to

mark its position.

2.

Find the centre of the semi-circle. Then draw in the normalin line

as shown in the diagram (right).

3. Set up the ray box as described in the previous two experiments.

Angle the ray as I diagram A, so that it goes straight through the

curved faced of the glass block and strikes the centre of the semi-

circle.4. Increase the angle until the refracted ray has just disappeared. Mark the position of the

ray. The ray is now striking the surface of the block at the critical angle.

5. Remove the glass block and the ray box. Draw in the path of the ray. Measure the

critical angle.

6. Repeat the experiment and find an average value for the critical angle.

If time permits repeat for other transparent material.

Extension

Explain this formula and use it to derive a formula for determining the critical angle.

n1sin1= n2sin2
http://www.freezeray.com/flashFiles/Refraction1.htmhttp://www.freezeray.com/flashFiles/Refraction1.htmhttp://www.freezeray.com/flashFiles/Refraction1.htmhttp://www.freezeray.com/flashFiles/Refraction1.htm


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Practical 475 NAME ______________________________________________________

Marks

Label incident ray and refracted ray

Label block AND normal

Arrows go towards middle point AND away from middle point

Critical angle = 43 or 42 degrees


48/79

Practical 480 NAME ______________________________________________________

Macleans CollegeIGCSE Physics

Convex lens

Equipment: power pack, bulb, lens, lens holder, metre ruler and screen

Method:

1. Set up the following

2. Adjust the position of the lens to get a clear image on the screen.

3. Record x and y in a table as shown below

4. Repeat for five more values of x (caution: some x values may have very large y values).

5. Determine the reciprocal of x and the reciprocal of y

6. Determine the sum of these reciprocals (

1

x +

1

y )

7. Determine the reciprocal of the sum of the reciprocals (

1

1x+1y )

Results

Copy and complete the table:

x y 1/x 1/y1

x +

1

y

1

1

x+1

y

8. Check the units for each column

9. Determine the focal length of the lens by measuring the distance from the lens to a

screen. The image on the screen must be clear and the object must be very far away

e.g. music block.

10.Comment on your last column of the table.


49/79

Practical 485 NAME ______________________________________________________

Macleans College


Focal length

Gear: thick convex lens, thin convex lens, lens holder, screen (white card), metre rule

When parallel rays of light go through a convex lens, they come together at

a point called the focus. The distance from this focus to the lens is the focal

length.

Rays from anything a long way away are

very nearly parallel. If you use a convex

lens to focus rays from a distant building

or tree, you can see a small image on a

screen. If the image is sharp, the screen is

at the principal focus. The distance from

the lens to the screen is the focal length.

Instructions

1 Arrange the lens, screen and metre rule as in the diagram. Light from a window must

be able to pass through the lens and reach the screen. The experiment works best if thelens and screen are in the darkest part of the room, opposite the window.

2 Move the screen backwards or forwards until you see a clear image of a distant tree or

building.

3 Measure the distance from the lens to the screen. This is the focal length of the lens.

4 Repeat the experiment at least three times. Find an average value for the focal length.

5 Find out by experiment which has the longer focal length, a thick lens or a thin lens.

6 find out by experiment which gives the bigger image on the screen, a thick lens or a thin

lens.


50/79

Practical 490 NAME ______________________________________________________

Macleans College


Dispersion

Gear: triangular GLASS prisms, power pack, ray-box with single slit, paper, ruler, screen,

protractor

Aim

Each wavelength of light has a unique refractive index. When white light pass through

different material the individual colours can be separated. This is called dispersion. You are

to investigate this phenomenon.

Instructions

Copy the table into your practical book.

1. Place the triangular prism in the middle of your page.

2. Shine a thin beam of white light into the prism so that dispersion is observed. You may

need to rotate either the prism or the ray box about the middle of the page.

3. Carefully draw the outline of the prism and the path of the light rays entering and

emerging from the prism.

4. Draw the probable path of the incident ray if the prism was absent (extend this to the

end of your page). This is called the straight through line.

5.

Carefully draw and extend the lines for the red, green and violet rays so they are 5-8 cm

in length.

6. Use your protractor to measure their angles from the straight through line and record

the data into your practical book.

7. Repeat the above using a different type of prism (either glass or perspex).

8. List ways to improve your results


51/79

Practical 500 NAME ______________________________________________________

Macleans College


Electrostatics

GearElectroscope, woollen cloth, perspex, plastic, nylon or glass (rods or sheets), OHT sheets

Aim

To observe some phenomena related to electrostatic charge

These activities are weather dependent. They work best on dry days. Humid or damp days

give poor results.

Instructions

1)

Read all of theses instructions before you start

2) Rub a plastic rod with a woollen cloth

3) Hold the plastic near the cap of the electroscope.

4) Observe the leaf.

5) Repeat but this time touch the cap of the electroscope.

6) What difference does this make?

7) Repeat and touch the cap two more times.

8)

Does this have any effect?

9) Repeat 1) with perspex and a woollen cloth

10)

Do you get the same result?

11) Find and list objects that do have the same effect (state what

they were rubbed with).

12)

List objects that do not (state what they were rubbed with).

Tabulate your results in a sensible way.

Extension

Explain what is meant by induced charges (p 180 Pople).


52/79

Practical 508 NAME______________________________________________________________

Macleans College


* Series or parallel circuit

Gear: Power packs, connecting wires, bulbs, voltmeter, ammeter and switch

Carry out the following instructions.

Record your observations and readings in your Practical Book.

Copy the following table.

Set up Fig. 1.1


53/79

Practical 508 NAME______________________________________________________________


54/79

Practical 510 NAME ______________________________________________________


Combined resistance

Gear: Power packs, bulbs, voltmeter, ammeter, switch and connecting wires


55/79

Practical 510 NAME ______________________________________________________


56/79

Practical 510 NAME ______________________________________________________

(k) Summarise your findings.


57/79

Practical 511 NAME ______________________________________________________

Macleans College


IV graphs

Gear:power supply, resistors (lamp, 100 ohm, motor), ammeter, 3 connecting wires

Aim

To observe current-voltage characteristics for some resistors

Instructions

1. Set up the circuit shown.

2 Draw a circuit diagram for it.

3 Copy and complete this table.

Potential

difference

Current Current Current

0.5

1.0

2.0

4.0

6.0

8.0

4 Check your current numbers have the same d.p . Include units in your table

5 Plot a graph of current (vertical) against voltage.

6 Repeat for different resistors7 What can you say about the resistance of a lamp, motor, carbon resistor (?)


58/79

Practical 516 NAME______________________________________________________________


Potential Divider

Gear: power pack, voltmeter (DMM), fixed resistor (approx 20 ohm), connecting wire, and

rheostat (large).

In this experiment you are to investigate the behaviour of a potential divider.

Instructions1.

Read the top right hand panel page 245 Pople.

2. Set up the lower circuit using the available rheostat and fixed resistor.

3. Make up a table showing the position of the slider on the rheostat and the output

voltage. Show six different positions for the length.

4. Swap the position of the fixed resistor and rheostat. The output voltmeter is across the

fixed resistor.

5.

Repeat step 3 above.6.

Explain how a rheostat can be used as a potential divider.


59/79

Practical 521 NAME______________________________________________________________

Macleans College


Magnet Field of a bar magnet

Aim: To observe magnetic field lines around bar magnets

Gear: 2 bar magnets, paper, iron filings, flat booklets

Instructions:

1. Place paper over a bar magnet as shown. Sprinkle iron filings. Tap paper.2. Observe patterns

3. Record field lines

4. Repeat for the following magnet arrangements

(a)

(b)

(c) (d)

N SS N

S N S N

S N

S N

S N

N S

Bar magnet under

sheet of paper


60/79

Practical 525 NAME______________________________________________________________

Macleans College


Magnetism 2

Aim: To plot magnetic field lines and show their directions using a plotting compass

Gear: bar magnet and charm (plotting) compass

Instructions:

1. Place bar magnet in the middle of your page & trace the edge

2. Place a charm compass touching the magnet on your page.

3. Slide the compass along the magnet. Observe the arrow changing directions

4. Slide the compass to one corner so that it points away from the magnet.

5. Mark that end of your compass N

6. Observe where the tip of the arrow would line up on your sheet.

7.

Use a sharp pencil to mark your sheet with a dot . where the tip of the arrow would be.8. Slide the compass so the tail of it is directly over the dot.

9. Repeat steps 6-8 until you are off the sheet or return back to the magnet.

10.Slide the compass to another position on the magnet

11.Repeat steps 6-10 until you have 5-6 curves on both sides of the magnet

12.Draw in the curves and show the direction of the field lines

Step 4

Step 6

Your diagram might look like this.

S N

S N

Extension:Place a second magnet 20 cm away and

repeat the process.

What do you think the pattern would

appear now?


61/79

Practical 540 NAME______________________________________________________________


Mapping the field round a magnet

Gear:bar magnets, paper, small compass (plotting compass)

The space around a magnet where you can find its magnetism is

called a magnetic field. If you sprinkle iron filings around a

magnet, you can see the field pattern. You can also plot the field

pattern using a small compass.

1 Put the magnet in the middle of the paper. Draw round the magnet

to mark its position. Keep the magnet and paper in the same place

for the rest of the experiment.

2 Put a dot on the paper near one end of the magnet. Place the

compass so that one end of its needle is next to the dot. Mark the

position of the other end of the needle with another dot.

3 Move the compass so that the first end of the needle points to the last

dot you made and so on until you have a row of dots whichreaches the magnet again or the edge of the paper.

4 Join up the dots with a smooth curve. You have

now drawn a field line.

5 Repeat from a different dot by the magnet. Do

this about ten times until you have drawn a full

pattern round the magnet.

More things to do

6 Find the field patterns around these magnets:

(a) (b)


62/79

Practical 542 NAME______________________________________________________________

Macleans College


Force on a current carrying wire

Gear:power pack, large horseshoe magnet, long wire

1. Place the long wire in the magnet as shown.

2. Switch on briefly.

3. Observe the movement.

4. Reverse the polarity of the power supply.

5. Observe the movement.

6.

Reverse the polarity of the large magnet.7. Is this what you expected?

List three ways to make the magnetic force stronger.


63/79

Practical 543 NAME______________________________________________________________

Macleans College


Electromagnetism 1

Oerteds Experiment

Aim: To show that the magnetic field is at right angles to the current

Gear: long wire, short wire, power supply, charm compass, lamp

Instructions

Place a compass on the table.

Use one long wire (and a short wire) to connect a lamp to a DC power supply. Test that it works- Turn off.

Move the long wire over the compass so that the needle is parallel to it.

Turn on and determine the direction of the magnetic field.

Repeat with the compass above the wire.

Try different situationsTurn the long wire so it is vertical and place the compass as close as possible to it.

Determine the direction of the magnetic field

Reverse the polarity and repeat.

Does the magnetic field remain in the same direction?
http://www.youtube.com/watch?v=p_bU2CInQDEhttp://www.youtube.com/watch?v=p_bU2CInQDEhttp://www.youtube.com/watch?v=p_bU2CInQDE


64/79

Practical 560 NAME______________________________________________________________

Macleans College


Electric Motor

Gear: crocodile clip, 2V power supply, Hodson Electric Motor Kit,

Extension:plastercine, string, stopwatch, electronic scales

The electric motor is an application of electromagnet force and current.

Instructions

1. Check that the kit contents are complete before you start

2.

Align and press the two halves of the rotor together until they click (fig.1)

3.

Insert axle to ensure rotor spins freely

4.

Remove axle and wind the coil with wire.

5. Form the commutator and hold in place with 2 rubber rings (fig. 2)

6. Thread wires through end plate and form the brushes with red and black wire (fig. 3).

7. Fit the two ends to the metal frame with the elastic band (fig. 4).

8. Fit the two magnets with opposite poles facing each other (fig. 5).

9. Fit the axle and fit the rotor between the ends and between the brushes

10. Check that the brushes press gently against the commutator loops.

11. Check that the rotor rotates freely 360o

12. Connect to a 2V DC supply (you may need to give an initial flick to start).

ExtensionUsing a small piece of adhesive tape attach a length of thread 1500 mm long to the rotor tube

(opposite end to the commutator). Hold the motor on its side on the edge of a bench so that

the string hangs down to the floor and free from obstructions. Tie a small mass to the end of

the thread and connect the motor to the power supply. Have some slack in the thread and start

the motor.

As soon as the mass begins to lift from the floor use a stopwatch to measure the time it takes

to raise a mass (eg 10 g) a height of (1 metre, perhaps).

Calculate the power of the motor in watts.


65/79

Practical 560 NAME______________________________________________________________

fig. 1 fig. 2

fig. 3 fig. 4

fig. 5


66/79

Practical 561 NAME______________________________________________________________

Macleans College


Efficiency of a motor

Aim: to determine the efficiency of an electric motor.

Gear: DC motor, ammeter, switch (or double throw switch), power supply, spool with cotton and mass,

retort stand etc.

Instructions

1.

Set up a motor in series with an ammeter, switch and 6V DC supply

2. Clamp to a retort stand on a bench.

3.

Tape a 1.2 m length of cotton with 10 g mass.

4.

Switch on to wind up the mass.

5. Stop immediately

6.

Unwind by reversing the terminals (or use a double throw switch)7. Record the current and voltage as the mass rises

(repeat a few times if necessary)

8. Measure the height the mass can travel.

9.

Time how long it takes to rise to that height

10.Use E = mgh to calculate work output

11.

Use E = VIt to calculate work input

12.Determine the efficiency =

x 100%

13.Repeat using different voltages eg 2V 4V 6V 10V

14.

Does the voltage affect the efficiency?

DC Supply


67/79

Practical 570 NAME______________________________________________________________

Macleans College


Capacitor

Gear: Y10 electronics kit (with resistors, transistor, capacitors and 9V battery), iron wool

In this experiment you are to investigate the behaviour of a capacitor.

Instructions

1. Read the bottom half of page 246 Pople.

2. Set up the circuit using an LED instead of the 6V lamp

3. Draw this circuit diagram carefully and label the parts.

4.

Observe the LED when the switch is turned on.

5. Reset the capacitor and repeat a few times

6.

Record your observations.

7.

Explain how the capacitor is used in this circuit.

8.

Change the capacitor and explain how the different capacitor affects the circuit.


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Practical 571 NAME______________________________________________________________


LDR

Gear: Y10 electronics kit (with resistors, transistor, LDR and 9V battery), iron wool

In this experiment you are to investigate the behaviour of a light dependent resistor.

Instructions

1. Read the top half of page 246 Pople.

2.

Set up the circuit using an LED instead of the 6V lamp

3. Draw this circuit diagram carefully and label the parts.

4. Observe the LED when the LDR is in bright light (under lights) and in the dark.

5. Record your observations.

6.

Swap the LDR with the 10 k ohm resistor.

7. Explain how this affects the LED.

8. Draw the circuit diagram carefully and label the parts.


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Practical 572 NAME______________________________________________________________


Thermistor

Gear: Y10 electronics kit (with resistors, transistor, thermistor and 9V battery), iron wool,

beaker of water, hair dryer

In this experiment you are to investigate the behaviour of a thermistor.

Instructions1.

Read page 247 Pople. Do not set up the circuit.

2. Copy the top circuit diagram on page 247 Pople using an LED instead of the 6V lamp,

a 9V battery instead of the 6V supply, a thermistor instead of the LDR and add an

ammeter in series with the LED.

3.

Set up your circuit and record observations.

4. Use cold water and a hair dryer to change the temperature of the thermistor.

5. Explain how a thermistor changes with temperature.


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Practical 573 NAME______________________________________________________________


Transistors

Gear: power pack, ammeter, connecting wire, iron wool, npn transistors (mounted), 6-12V

lamp, 2 x 1.5 V cells

In this experiment you are to investigate the behaviour of a transistor.

Instructions1.

Read page 244 Pople.

2. Set up circuit A on Page 244 Pople and add an ammeter in series with the lamp.


4. Draw circuit B with ammeter.

5.

Set up circuit B and turn on then off the 1.5V supply to the base of the transistor.

Repeat until you know what that part of the circuit does.


7.

Use the terms baseemitter and collectoremitter to explain the behaviour of an

npn transistor.


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Practical 580

Macleans College


Electronic Circuits 1

Set up your circuit with a 1K variable resistor - Draw a circuit diagram for it

In light the LDR prevents the LED from working.

In dark the LDR allows the LED to work.

Describe what happens to the LED when the resistor is turned from minimum to maximum resistance (or vice

versa). Determine the resistance when the LED just starts to operate (or when it just stops operating).

Explain why.

The transistor turns on when the voltage across Vbe > 0.6V

The total V across the fixed resistor and variable resistor is 9V

If the resistance of the variable resistor greater than about 84 ohms the voltage is greater than 0.7 V

This will cause the transistor to turn on so the LED lights up.

If the resistance of the variable resistor less than about 84 ohms the voltage is less than 0.7 V

This will cause the transistor to turn off so the LED is off.

Variable Resistor

TransistorWhite (left)

Red (Up)

Black (Down)

LED

Red (Up)

Black (Down)

Resistor

Brown-

Black-

Red

(Gold)


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Set up this second circuit- use your hand to darken the LDR / use a lamp to provide more light

1 It lights up in the dark

2 EXPLAINATIONS

1 LDR has low resistance in light and high resistance in the dark

2

In the classroom the light level is low (darkish)3 So LDR has high resistance

4 So VLDR= VBEis high (>0.6V)

5 So Transistor turns on

6

So LED is on

7 Shine light (from torch) onto LDR lowers the resistance and may drop VBEbelow 0.6V so LED turns

off

3 With 22K replacing 1K then VLDR has a much smaller VBEso LED probably off or needs less light (from

torch) to turn off -

In dark (or in classroom), the LDR has high resistance, so its voltage is > 0.6V so transistor is turned on so LED

is on.

In bright light (use 12V lamp), the LDR has low resistance, so its voltage < 0.6V so transistor is turned off so

LED is off.

Summary: LED is on unless LDR in bright light


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Replacing the 1k resistor with the 22000resistor means that VLDRhas lower voltage initially

{it must be much darker so that the LDR resistance is much higher to allow it to get more than 0.6V or more as

its share in the potential divider.

e.g. 1000: 100= 8.2V : 0.8V

22000: 100= 8.9V : 0.1V (so not enough)}


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2 Potentiometer replaces LDR.

With the battery switch pressed on, turn the

potentiometer slowly one way and the other and

repeat.

What use is the potentiometer in this circuit?

Adjust potentiometer until LED just stays on.

Remove potentiometer and measure its resistance.

This is the largest resistance to just turn on thetransistor

3 Potentiometer in series with LDRAdjust potentiometer until LED just stays on.

Move your fingers over the LDR

Describe and explain what happens.

4 Temperature controlReplace the capacitor with a thermistor

Use a hairdryer to turn off the LED.

Explain how we can use the hairdryer to turn on the

LED.


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4 Moisture detectorPut the probes in moisture. Try

using your fingers

5 Courtesy lightPush the button for 2 seconds. What

happens after you release the switch?

6 Delay

Replace the yellow wire with the 100k potentiometer. Time it to light up.

This does not work the second time as the capacitor is now charged up.

Discharge it by connecting the + to of the capacitor for a second (any bare wire will do)

Repeat with the potentiometer dial in different positions. Draw a circuit diagram and explain what happens.


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8 RelayThese will be phased out when ssr (solid state relays)

become more easily assessable.

Press your finger on the battery switch - the relay clicks

and both grain of wheat lamps glow.

The lamp in the yellow circuit is dim while the other

lamp is bright.

Take your finger off and the relay clicks off.Repeat slowly and the same happens but repeat quickly

and it doesnt.

The relay acts as a latch for the white circuit.

Initial push opens the latch so white circuit is open.

When the switch is open the white circuit stays off until

inductor (relay discharges).


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In light the LDR prevents the LED from working.

In dark the LDR allows the LED to work.

In light, the LDR has low resistance, so its share of the voltage of the potential

divider is not enough to switch the transistor on.

In dark, the LDR has higher resistance, so its share of voltage is above 0.6V needed

to turn the transistor on.

The 22000resistor means that it must be much darker so that the LDR resistance

is much higher to allow it to get more than 0.6V or more as its share in the potential

divider.

e.g. 1000: 100= 8.2V : 0.8V

22000: 100= 8.9V : 0.1V (so not enough)

22000: 2000= 8.3V : 0.6V (darker, and transistor switches on)

LDR

LEDResistor

1k

Transistor

LEDResistor

1k

1000FTransistor

LEDResistor

22k

1000FTransistor

Resistor

22kRelay

Motor


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Practical 600 NAME______________________________________________________________

Macleans College


Radioactivity

Gear: drawing pins

Radioactive material transforms into different nuclei. In doing so it releases energy in the

form of kinetic energy or electromagnetic waves.

We will investigate thedecaypattern by using drawing pins. The pins that point upwards

can be considered as radioactive atoms and the pins that point down (angle) can be

considered as decayed atoms.

Instructions

1. Count the number of pins supplied to you (approx. 100-200). This is throw 0

2.

Pour them onto your table top. This is throw number 1.3. Count the number of pins that are pointing upwards (radioactive

atoms)

4. Remove all pins that face down (decayed atoms)

5.

Throw again using only radioactive atoms. This is throw number

2.

6.

Repeat several times until all of the pins are used up.

7. Continue the table for as many throws necessary.

Throw

number

Number of

radioactiveatoms

0

1

2

3

4

5

6
http://www.upscale.utoronto.ca/GeneralInterest/Harrison/Flash/Nuclear/Decay/NuclearDecay.htmlhttp://www.upscale.utoronto.ca/GeneralInterest/Harrison/Flash/Nuclear/Decay/NuclearDecay.htmlhttp://www.upscale.utoronto.ca/GeneralInterest/Harrison/Flash/Nuclear/Decay/NuclearDecay.htmlhttp://www.upscale.utoronto.ca/GeneralInterest/Harrison/Flash/Nuclear/Decay/NuclearDecay.html


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Practical 600 NAME______________________________________________________________

8. Graph the classs number of Number of radioactive atoms on the vertical axis against

the Throw number.

9. Determine the half life of this by halving the initial number of pins and finding the

corresponding time.

10.

Repeat for different initial values and finding the corresponding time interval.

Documents

All IGCSE Physics Practicals 2015