LEVEL 7
PHYSICS
QUESTION
BOOKLET
Name:...... Tutor Group:......
1.
(a)Each of the four objects shown above started at room temperature.
Now they are all at different temperatures, as described by the labels.
(i)Which object is at the highest temperature?
......
1 mark
(ii)Which object has lost thermal energy?
......
1 mark
(iii)Which object has had the largest gain in thermal energy?
......
1 mark
(b)Omar puts a hot steel ball into a beaker of cold water. He waits until the temperatures of the ball and the water are the same.
From his results, he calculates that:
the thermal energy stored in the steel ball has fallen by 3770 J;
the thermal energy stored in the water has risen by 2940 J.
The energy stored in the water rose by less than 3770 J. What has happened to the other 830 J?
......
1 mark
Maximum 4 marks
2.A pupil has two well-insulated containers of water at 20° C. She takes two identical blocks of aluminium, both at 100° C, and puts one into container A and the other into container B. The temperature of the water rises in each container until it reaches a steady value. Her results are shown in the table.
(a)Explain why the final temperature of the water is lower in container B.
......
1 mark
(b)What is the final temperature of each aluminium block?
The block in container A is at …………………………. ° C.
The block in container B is at …………………………. ° C.
1 mark
(c)Which of the identical aluminium blocks transferred more energy to the water?
Explain your reasoning.
......
1 mark
Maximum 3 marks
3.Sam turns his bicycle upside down and turns the pedals fast so that the back wheel spins.
Sam holds a piece of card close to the back wheel.
The spokes hit the piece of card and Sam hears a ‘musical’ tone.
(a)Explain why the card produces a ‘musical’ tone.
......
1 mark
(b)When the spokes hit the piece of card, the wheel slows down
(i)Describe the energy change which occurs as the wheel slows down.
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1 mark
(ii)Describe and explain what will happen to the pitch of the ‘musical’ tone as the wheel slows down.
......
2 marks
Maximum 4 marks
4.(a)In an iron rod the particles vibrate. If one end of an iron rod is heated, the vibrating particles transfer energy to neighbouring particles which are not vibrating so violently.
What is this process called?
……….………………………………
1 mark
(b)An electric immersion heater is put at the bottom of a large tank of water.
The water next to the heater becomes warm.
(i)What will happen to the warmed water next to the heater?
Give a reason for your answer.
…………………………………………………………………………………
…………………………………………………………………………………
2 marks
(ii)Why can heat not be transferred in this way in an iron rod?
…………………………………………………………………………………
1 mark
(c)In a liquid, some of the particles have enough kinetic energy to escape from the surface.
This process happens even when the liquid is well below its boiling point.
(i)What is this process called? ……………………………………………….
1 mark
(ii)How will this affect the temperature of the liquid left in the container?
…………………………………………………………………………………
1 mark
Maximum 6 marks
5.A flywheel is a rotating wheel which is used to store energy.
(a)Energy must be transferred to a flywheel to make it rotate. How is the energy in the rotating flywheel classified? Tick the correct box.
as chemical energy
as kinetic energy
as potential energy
as thermal energy
1 mark
(b)A flywheel is rotating at a high speed. No energy is being supplied to it. The flywheel is used to turn a dynamo, and the energy from the dynamo is used to light a bulb.
(i)The bulb is left connected until the flywheel stops rotating. Not all the energy stored in the flywheel is transferred to the bulb. Some of it is lost. Give two places from which it is lost, and explain howitislost.
1......
2......
2 marks
(ii)The experiment is repeated using a different bulb which gives out more energy each second. Compared to the first light bulb, describe how the second light bulb will affect the motion of the flywheel, and explain your answer.
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2 marks
Maximum 5 marks
6.The drawing below shows a solar panel fixed to the roof of a house in Britain.
(a)Daniel measured the energy output from this solar panel during one day in June. The graph below shows his results.
(i)Why does the energy output from the solar panel vary during the day?
......
1 mark
(ii)Daniel used the solar panel to run a motor.
The motor needs 0.7 kJ/s to run at full speed.
Use the graph to find out how long Daniel’s motor would run at full speed.
...... hours
1 mark
(b)Daniel measured the energy output from a different solar panel.
This type of solar panel turns so that it always faces the Sun.
The graph below shows the energy output for this panel during one day in mid-summer.
(i)On the graph above draw another curve to show how the energy output for this solar panel might vary on a day in mid-winter.
2 marks
(ii)Between 7am and 7pm the solar panel turns through an angle of 180°.
Calculate the angle the solar panel turns through each hour.
......
...... degrees
1 mark
maximum 5 marks
7.(a)The diagram below shows a car park barrier.
(i)Calculate the turning moment produced by the barrier about the pivot.
Give the unit.
......
2 marks
(ii)The barrier is horizontal. The weight of the barrier is balanced by an iron counterweight. Calculate the downward force produced by the counterweight.
......
...... N
1 mark
(b)An electromagnet is placed beneath the iron counterweight as shown below.
When the switch is closed the barrier rises.
Explain how the electromagnet can be used to raise the barrier.
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......
2 marks
maximum 5 marks
8.(a)A pupil makes a small coil of copper wire and passes an electric current through it.
The pupil places a small magnet near the coil.
The magnet is attracted towards the coil. The pupil turns the magnet around so that theSouth pole is nearest the coil.
What effect, if any, will this have?
……….………………………………………………………………………………
1 mark
(b)The pupil uses the coil and the magnet to make a simple ammeter to measure thecurrentthrough a bulb.
not to scale
(i)The paper clip is used to balance the weight of the magnet.
Why is the paper clip further away from the pivot than the magnet is?
…………………………………………………………………………………
1 mark
(ii)Explain how a current in the coil makes the straw pointer move.
…………………………………………………………………………………
…………………………………………………………………………………
2 marks
(iii)The pupil places a piece of soft iron in the middle of the coil.
Describe and explain how this will affect the reading on the scale when thesamecurrent flows through the coil.
…………………………………………………………………………………
…………………………………………………………………………………
2 marks
Maximum 6 marks
9.A pupil wound a coil of copper wire around a glass tube and connected the wire to a battery. She placed a compass at each end of the tube and one compass beside the tube as shown.
(a)(i)Complete the diagram by drawing arrows in compasses X and Y to show the direction of the magnetic field.
2 marks
(ii)Draw an arrow in the middle of the glass tube to show the direction of the magnetic field in the glass tube.
1 mark
(iii)When the switch is opened, in which direction will the three compass needlespoint?
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1 mark
(b)Give one way to reverse the magnetic field around the glass tube
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1 mark
(c)Two pieces of iron are placed inside the glass tube.
(i)When the switch is closed, the magnetic field is the same as in the
diagram opposite. The pieces of iron become magnetised.
Label the four poles on the pieces of iron.
1 mark’
(ii)When the switch was closed, the pieces of iron moved.
Explain why they moved.
......
1 mark
Maximum 7 marks
10.The diagram shows a rectangular coil and circuit. It has two iron rods in it.
The rods are parallel and touching. They are free to move.
(a)When the switch is closed, the two rods move apart.
(i)Explain why this happens.
......
......
2 marks
(ii)The switch is then opened to break the circuit. What, if anything, happens to the two iron rods?
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1 mark
(b)One of the two iron rods is taken out and replaced with a brass rod.
The rods are parallel and touching.
What, if anything, will happen to the rods when the switch is closed?
Explain your answer.
......
......
2 marks
Maximum 5 marks
11.A pupil fixes a small electromagnet close to a thin springy steel sheet. The device acts like a small speaker. She connects a battery and switch to the electromagnet as shown.
(a)(i)When the pupil closes the switch, what will happen to the steel sheet?
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1 mark
(ii)The pupil opens the switch again. What will happen to the steel sheetnow?
......
1 mark
(iii)If the pupil had connected the battery the other way round, what difference would this have made to your answer to part (i)?
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1 mark
(b)The pupil removes the battery and switch. She connects the electromagnet to a power supply which switches the current on and off 1000 times each second. The steel sheet vibrates and makes a sound.
(i)She then adjusts the power supply so that the current is switched on and off 3000 times each second.
What difference does this make to the pitch of the sound?
Give a reason for your answer.
......
......
2 marks
(ii)The pupil now adjusts the power supply so that the current is larger. Explain why this makes the sound louder.
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1 mark
Maximum 6 marks
12.Circuit breakers are switches which open when the current becomes too large. The diagram shows a simple circuit breaker. The springy piece of metal pushes down on the iron rocker, and this holds the switch contacts together.
(a)(i)There is a current in the coil in the circuit breaker. What is the purpose of the coil?
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1 mark
(ii)What is the purpose of the soft iron core in the coil?
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1 mark
(b)Give two properties of iron which make it a good choice of material for the rocker.
1......
2......
2 marks
(c)The diagram below shows the circuit breaker with the switch contacts open.
Why do the switch contacts separate when the current becomes too large?
......
1 mark
Maximum 5 marks
13.The diagram shows an electromagnetic relay. The relay is connected in a circuit with a battery, a lamp and a switch.
(a)(i)Give the name of a suitable material to use for the core of the electromagnet.
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1 mark
(ii)Give the name of a suitable material to use for the armature.
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1 mark
(b)(i)Explain why the contacts come together when the switch is closed.
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......
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3 marks
(ii)When the switch is now opened, the bulb stays on. Explain why.
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1 mark
Maximum 6 marks
14.John connects up the circuit shown below.
The bulb is not bright enough. His friend suggests four circuits which could be used to make the bulb brighter.
(a)Which is the correct circuit to use: A, B, C or D? ......
1 mark
Next John sets up circuit E and notes the reading on the ammeter.
He then places another bulb in the circuit, to make circuit F. He notes the ammeter reading in circuit F.
(b)How will the ammeter reading in circuit F compare with that in circuit E?
The reading in F is ......
1 mark
Explain you answer......
......
1 mark
(c)Draw a circuit diagram in which two bulbs are lit as brightly as the bulb in circuit E, and the ammeter reading is the same as in circuit E.
1 mark
Maximum 4 marks
15.A remote-controlled car was timed over a period of 10 seconds.
A graph of distance against time is shown below.
(a)Describe the motion of the car between:
(i)2 seconds and 6 seconds;
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1 mark
(ii)9 seconds and 10 seconds.
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1 mark
(b)Calculate the average speed of the car between 0 and 10 seconds.
Give the unit.
......
2 marks
(c)The diagram below shows two of the forces acting on the car when it is moving.
(i)When the motor was switched off, the car slowed down and then stopped.
While the car was slowing down, which of the following was true? Tick the correct box.
Friction was zero and the forwardforce was greater than zero. /
The forward force was zero and
friction was greater than zero. /
Friction was zero and the forward
force was zero. /
The forward force and friction were
both greater than zero. /
1 mark
(ii)Use the graph to find the time when the car started to slow down.
The car started to slow down after ...... s.
1 mark
Maximum 6 marks
16.A video recorder is loaded with a tape which plays for 180 minutes.
The length of the tape is 260 m.
(a)(i)Calculate the speed of the tape, in metres per minute.
……………………………………….……………………………………….
……………………………………….……………………………… m/min
1 mark
(ii)What is the speed of the tape in metres per second?
……………………………………….…………………………………. m/s
1 mark
(b)To rewind the tape quickly, a different motor is used, which rewinds the tape at amaximum speed of 1.08 m/s.
(i)At this speed, how long would it take to rewind the tape completely?
Give the units.
……………………………………….……………………………………….
……………………………………….……………………………………….
1 mark
(ii)In fact, it takes slightly longer than this to rewind the tape.
Explain why.
……………………………………….……………………………………….
1 mark
Maximum 4 marks
17.(a)Megan was doing time-trials on her bike around a 400 metre horizontal track.
(i)She took 32 seconds to travel 400 m.
What was her average speed? Give the unit.
......
......
1 mark
(ii)Compare the forward force on the bike with the backward force on the bike when Megan was travelling at a constant speed.
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1 mark
(b)Megan then crouched down over the handlebars to make herself more streamlined, as shown below.
She continued to pedal with the same force as before.
Compare the forward and backward forces on Megan and her bike now.
......
1 mark
Explain your answer.
......
1 mark
maximum 4 marks
18.(a)The ‘two second rule’ is a rule for car drivers. The rule is as follows:
‘Leave enough space between you and the vehicle in front so that you can pull upsafely if it suddenly slows down or stops. . . A two second time gap may be sufficient. . . Use stationary objects (eg lamp-posts) to help you keep a two secondgap.’
(The Highway Code, 1993)
(i)The traffic is moving at 20 m/s, and a driver is keeping to the ‘two second rule’.
What is the distance between the driver and the car in front?
......
1 mark
(ii)The traffic increases its speed to 25 m/s, but the driver stays the same distance from the car in front.
She sees the car in front pass a lamp post.
How long will it take her to reach the same lamp post?
......
...... s
1 mark
(b)The driver decides to check her speedometer while driving along a motorway.
She measures how long it takes her to travel 6 km. It takes her exactly 4 minutes.
What was her speed in km/h? Show your working.
......
...... km/h
2 marks
Maximum 4 marks
19.Speed cameras are used to detect motorists who break the speed limit. A number of lines 2 m apart are painted on the road. As a speeding car crosses the painted lines, the camera takes two photographs, 0.5 s apart.
(a)(i)How far did the car move between the two photographs?
Give the correct unit.
......
1 mark
(ii)How fast is the car in the photographs moving?
...... m/s
1 mark
(b)It takes 0.0002 s to take each photograph.
How far does the car move while the speed camera is taking one photograph?
...... … m
1 mark
(c)The speed camera gives out bright flashes to provide enough light for the photographs.
How does the light from the flash get back to the camera to produce the photographs?
......
......
1 mark
Maximum 4 marks
20.The diagram shows a crane lifting a load. The counterweight and the load are balanced.
(a)The load is moved away from the pivot, to the right.
(i)What happens to the turning moment produced by the load?
......
1mark
(ii)What should happen to the counterweight to keep the arm balanced?
......
1mark
(b)Aload of 5000 N is placed 8 m from the pivot.
(i)What is the turning moment of the load? Give the unit.
......
......
2marks
(ii)How far from the pivot must the 10000 N counter weight be placed in order to balance the load?
...... m
1mark
(iii)The counterweight is placed 3 m from the pivot.
What load could now be balanced 8 m from the pivot?
......
...... N
1mark
Maximum 6 marks
21.Alex has a 100 cm ruler pivoted at the centre. She ties a balloon filled with carbon dioxide 16 cm from the pivot, as shown below.
The total weight of the balloon and carbon dioxide is 0.06 N.
(a)The ruler becomes unbalanced.
Calculate the turning moment the balloon produces about the pivot on the ruler. Give the unit.
......
......
2 marks
(b)Alex ties another similar balloon, filled with helium, 48 cm from the pivot.
The helium balloon exerts an upward force on the ruler.
The ruler is balanced as shown below.
(i)When the ruler is balanced, what turning moment must the helium balloon produce about the pivot?
......
1 mark
(ii)Calculate the upward force exerted by the helium balloon on the ruler.
......
...... N
1 mark
Maximum 4 marks
22.Gareth is trying to release a nut with a spanner. The diagram shows the size of the force he is exerting and where this force acts on the handle.
(a)The spanner applies a moment, or turning effect, to the nut. Calculate the size of this moment or turning effect. Give the units.
......
......
2 marks
(b)Give two ways in which Gareth could increase the moment he applies using this spanner.