Download PHYSICS: Higher Question Paper Part 2

Physics P3 Higher Questions Part 2
Q1.
The diagram shows a glass prism.
(i)
Explain why refraction has not occurred at point X.
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(1)
(ii)
(A)
Give the full name for the process which has occurred at point Y.
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(1)
(B)
Explain why this process has occurred.
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(2)
(Total 4 marks)
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Q2.
(a)
The drawing shows a small transformer used to recharge the battery in a 4.2 V
mobile phone from a 230 V mains supply.
Explain how you know that this is a step-down transformer.
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(1)
(b)
A transformer consists of an insulated coil of wire, called the primary coil, on one
side of a core. Another coil of insulated wire, called the secondary coil, is on the
other side.
Give two features of the core.
1 ..................................................................................................................................
2 ..................................................................................................................................
(2)
(Total 3 marks)
Q3.
The drawing shows an experiment using a low voltage supply, a joulemeter, a small
immersion heater and a container filled with water.
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The immersion heater is designed for use in a tropical fish tank. It is connected to a
step-down transformer supplied by 230 V a.c. mains.
The inside of a step-down transformer consists of three main parts. Name the three parts
and briefly describe them. You may add to the diagram to help you to answer.
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(Total 4 marks)
Q4.
Pigs have a layer of fat in their skin. Underneath the fat is a layer of muscle.
Ultrasonic waves are used to measure the thickness of the layer of fat. An ultrasound
transmitter and detector are attached to the skin of the pig.
(a)
Explain why ultrasound can be used to measure the thickness of the layer of fat.
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(2)
(b)
The oscilloscope does not measure distance directly.
(i)
What does the oscilloscope measure in this case?
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(1)
(ii)
What other information is needed to calculate the thickness of the layer of fat
in a pig?
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(1)
(Total 4 marks)
Q5.
The diagram shows the image IC formed by a lens, of an object OB a long way from
it. The points F mark the focal points of the lens.
(a)
Describe, either by writing below or drawing on the diagram, how the size and
position of the image changes:
(i)
when the object OB is moved towards the focal point F.
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(ii)
when the object OB is moved past F to a point nearer the lens than the
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focal point.
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(4)
(b)
Explain how a converging lens in a camera is used to produce sharp images on the
film when the object is a long distance away from the camera, and when it is close
to the camera.
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(3)
(Total 7 marks)
Q6.
(a)
An appliance in a house has a transformer. The transformer is used to reduce
the voltage to the level needed by the appliance.
The diagram shows the transformer.
(i)
Name the material used for the core of the transformer.
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(1)
(ii)
The transformer has 10 000 turns on the input side and 2000 turns on the
output side. If the mains voltage of 240 volts is applied to the input, calculate
the output voltage. You may find the following information helpful:
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(3)
(b)
Explain, in terms of magnetic fields, how a transformer works.
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(4)
(c)
A 12 V car battery is connected to the input leads of the transformer. It is hoped to
reduce the voltage to 2.4 V in order to run a small motor. When the output voltage is
measured it is found to be zero.
Explain why the output voltage is zero.
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(2)
(Total 10 marks)
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Q7.
The diagram shows apparatus used to demonstrate the electric motor effect. When
he switch is closed the wire moves.
(i)
Draw an arrow on the diagram to show the direction the wire moves.
(1)
(ii)
Explain why the wire moves.
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(2)
(Total 3 marks)
Q8.
The diagram shows a spanner being used to undo a tight nut.
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The nut was tightened using a moment of 120 newton metres.
Use the following equation to calculate the force needed to undo the nut. Show clearly
how you work out your answer.
moment = force × perpendicular distance from pivot
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Force = ............................................. N
(Total 2 marks)
Q9.
(a)
The diagram represents a simple transformer used to light a 12 V lamp. When
the power supply is switched on the lamp is very dim.
(i)
Give one way to increase the voltage at the lamp without changing the power
supply.
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(1)
(ii)
What is meant by the iron core being laminated?
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(1)
(b)
Electrical energy is distributed around the country by a network of high voltage
cables.
(i)
For the system to work the power is generated and distributed using
alternating current rather than direct current. Why?
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(1)
(ii)
Transformers are an essential part of the distribution system. Explain why.
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(2)
(iii)
The transmission cables are suspended high above the ground. Why?
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(1)
(c)
The power station generates 100 MW of power at a voltage of 25 kV. Transformer
A, which links the power station to the transmission cables, has 44 000 turns in its
275 kV secondary coil.
(i)
Write down the equation which links the number of turns in each transformer
coil to the voltage across each transformer coil.
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(1)
(ii)
Calculate the number of turns in the primary coil of transformer A. Show
clearly how you work out your answer.
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Number of turns = ........................................
(2)
(d)
The diagram shows how the cost of transmitting the electricity along the cables
depends upon the thickness of the cable.
(i)
Why does the cost due to the heating losses go down as the cable is made
thicker?
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(1)
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(ii)
By what process is most heat energy lost from the cables?
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(1)
(Total 11 marks)
Q10.
(a)
The diagram shows a lens used as a magnifying glass. The position of the
eye is shown and the size and position of an object standing at point O.
(i)
What type of lens is shown in the diagram?
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(1)
(ii)
Two points are marked as F. What are these points?
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(1)
(iii)
What is the name of the straight line which goes through the point F, through
the point L at the centre of the lens, and through the point F on the other side?
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(1)
(iv)
On the diagram, use a ruler to construct accurately the position of the image.
You should show how you construct your ray diagram and how light appears
to come from this image to enter the eye.
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(5)
(v)
The image is virtual. What is a virtual image?
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(1)
(b)
The lens shown in the diagram in part (a)(iv) can be used in a camera to produce a
real image.
Explain why a real image must be produced in a camera and how the object and
the lens are positioned to produce a real image which is smaller than the object.
Do not draw a ray diagram as part of your answer.
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(3)
(Total 12 marks)
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Q11.
A transformer is used to reduce the 230 V a.c. mains to the 12 V supply required for
the lighting system. The transformer has 1150 turns on its primary coil.
(i)
Write down the equation which links the number of turns of each transformer coil to
the voltage across each transformer coil.
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(1)
(ii)
Calculate the number of turns on the secondary coil of the transformer. Show
clearly how you work out your answer.
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number of turns on the secondary coil = .........................
(2)
(Total 3 marks)
Q12.
The picture shows a pre-natal scan obtained using ultrasonic waves.
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(i)
Explain how ultrasonic waves are used to produce the image of an unborn baby.
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(2)
(ii)
Give another use for ultrasonic waves.
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(1)
(Total 3 marks)
Q13.
The London Eye is the largest observation wheel in the world.
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The passengers ride in capsules. Each capsule moves in a circular path and accelerates.
(a)
Explain how the wheel can move at a steady speed and the capsules accelerate at
the same time.
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(2)
(b)
In which direction does each capsule accelerate?
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(1)
(c)
What is the name of the resultant force that causes the capsules to accelerate?
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(1)
(d)
The designers of the London Eye had to consider three factors which affect the
resultant force described in part (c).
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Two factors that increase the resultant force are
•
•
an increase in the speed of rotation
an increase in the total mass of the wheel, the capsules and the
passengers.
Name the other factor that affects the resultant force and state what effect it has on
the resultant force.
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(1)
(Total 5 marks)
Q14.
(a)
This notice is on the back of a television set.
The transformer used in the television set has 75 turns on its primary coil. The
potential difference (p.d.) across the primary coil is 230 volts and the p.d. across the
secondary coil is 32 200 volts.
Use the equation below to calculate the number of turns on the secondary coil.
Show clearly how you work out your answer.
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Number of turns on the secondary coil = ....................
(2)
(b)
The diagram shows the structure of a transformer.
Explain how the transformer works.
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(3)
(Total 5 marks)
Q15.
Ultrasound can be used in industry for detecting internal cracks in metals.
(a)
State two features of ultrasound.
1 ..................................................................................................................................
2 ..................................................................................................................................
(2)
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(b)
The diagram shows an ultrasound transmitter and detector fixed to the front of a
metal block. The block has an internal crack.
The diagram below shows the screen of the oscilloscope connected to the detector.
(i)
Explain why pulse A and pulse B occur.
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(2)
(ii)
The metal block is 120 mm from front to back. What is the distance, in mm,
from the front of the block to the internal crack?
Distance = .................... mm
(1)
(Total 5 marks)
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Q16.
(a)
The diagram shows a transformer.
(i)
Is the transformer in the diagram being used as a step-up transformer or as a
step-down transformer?
Put a tick ( ) in the box next to your answer.
a step-up transformer
a step-down transformer
Explain your answer.
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(1)
(ii)
Why is insulated wire, and not uninsulated wire, used to make the coils?
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(1)
(iii)
Why is the core made of iron?
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(1)
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(b)
A transformer has 500 turns on its primary coil and 7500 turns on its secondary coil.
The potential difference across the primary coil is 150 volts.
Use the equation in the box to calculate the potential difference across the
secondary coil.
Show clearly how you work out your answer.
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Potential difference across the secondary coil = .............................. volts
(2)
(c)
Step-down transformers are used between power lines and people’s houses.
Explain why.
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(2)
(d)
Before 1926, large towns had their own local power stations. After 1926, these
power stations were connected to form the National Grid.
Explain the advantage of having a National Grid system.
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(2)
(Total 9 marks)
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Q17.
Tractors are often used on sloping fields, so stability is important in their design.
On the diagram, the centre of the X marks the centre of mass of the tractor.
(a)
Explain why the tractor has not toppled over. You may add to the diagram to help
you to explain.
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(3)
(b)
Give two features of the tractor which affect its stability and state how each feature
could be changed to increase the tractor’s stability.
Feature 1 .....................................................................................................................
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Feature 2 .....................................................................................................................
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(2)
(Total 5 marks)
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Q18.
(a)
The diagram shows a child’s mobile. The mobile hangs from point P on the
ceiling of the child’s bedroom.
(i)
Mark the position of the centre of mass of the mobile by drawing a letter X on
the diagram. Do this so that the centre of the X marks the centre of mass of
the mobile.
(1)
(ii)
Explain why you have chosen this position for your letter X.
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(2)
(b)
The diagram shows a device which helps to prevent a ladder from falling over.
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Use the term centre of mass to explain why the ladder, in the situation shown, is
unlikely to topple over.
You may add to the diagram to illustrate your explanation.
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(3)
(Total 6 marks)
Q19.
(a)
The diagrams show oscilloscope traces for the same musical note played on
two different instruments. The oscilloscope settings are not changed.
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(i)
How can you tell, from the diagrams, that it is the same musical note?
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(1)
(ii)
How can you tell, from the diagrams, that the musical note has been played
on different instruments?
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(1)
(b)
This passage is from an electronics magazine.
Electronic systems can be used to produce ultrasound waves.
These waves have a higher frequency than the upper limit for
hearing in humans.
Ultrasound waves are partially reflected when they meet a
boundary between two different media.
(i)
Approximately what is the highest frequency that humans can hear?
State the number and the unit.
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(1)
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(ii)
What does the word media mean when it is used in this passage?
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(1)
(iii)
What happens to the ultrasound which reaches the boundary between two
different media and is not reflected?
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(2)
(Total 6 marks)
Q20.
This page is from a science magazine.
The Red Planet
The two natural satellites, or moons, of Mars are Phobos (fear) and Deimos
(terror). They are named after the horses which pulled the chariot of Mars, the god
of war in the mythology of Ancient Greece.
Phobos takes less than eight hours to orbit Mars and gets slightly closer every time
it does so. Scientists predict that in about 100 million years time it will either be
ripped apart by the gravitational force or will crash onto the surface of Mars.
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(a)
Suggest how scientists have arrived at their prediction of about 100 million years.
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(2)
(b)
The centripetal force on Phobos is gradually changing as it orbits Mars.
Is the force increasing or decreasing?
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Explain your answer.
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(2)
(c)
Scientists expect that the mass of Mars and the mass of Phobos will not increase.
Explain what will happen to the gravitational force on Phobos as it orbits Mars.
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(2)
(Total 6 marks)
Q21.
The diagram shows the basic structure of a transformer.
(a)
Explain how a transformer works.
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(5)
(b)
A transformer is used to change the 230 volt mains electricity supply to the 12 volts
needed to operate a low voltage halogen lamp. The current through the halogen
lamp is
4 amps.
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Calculate the current drawn by the transformer from the mains electricity supply.
Assume that the transformer is 100 % efficient.
Write down the equation you use, and then show clearly how you work out your
answer.
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Current = ........................................... amps
(2)
(Total 7 marks)
Q22.
A student wants to weigh himself but the only balance available is a newtonmeter
that measures up to 200 newtons.
The diagram shows how the student solved the problem using moments.
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(a)
Use the information in the diagram to calculate the weight of the student given by
this method.
Write down the equation you use, and then show clearly how you work out your
answer and give the unit.
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Weight = ....................................
(5)
(c)
Even though all the measurements are accurate the student’s weight obtained by
this method is inaccurate.
Explain why.
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(2)
(Total 7 marks)
Q23.
Tractors are often used on sloping fields, so stability is important in their design.
On the diagram, the centre of the X marks the centre of mass of the tractor.
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(a)
What is meant by the term centre of mass?
........................................................................................................................
........................................................................................................................
(1)
(b)
Explain how the design of the tractor could be changed in order to increase the
tractor’s stability.
........................................................................................................................
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........................................................................................................................
(2)
(c)
Explain why the tractor does not topple over. You may add to the diagram to help
your explanation.
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(3)
(Total 6 marks)
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Q24.
The diagram shows a ray of light passing through a diverging lens.
(a)
Use the information in the diagram to calculate the refractive index of the plastic
used to make the lens.
Write down the equation you use, and then show clearly how you work out your
answer.
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Refractive index = ..................................
(2)
(b)
The focal length of the lens is 5 cm. A student looking through the lens sees
the image of a pin.
Complete the ray diagram below to show how the image of the pin is formed.
(3)
(Total 5 marks)
Q25.
The fairground ride called ‘The Rotor’ is a large cylinder which rotates. When the
cylinder reaches its maximum speed the floor drops away and the riders inside the
cylinder are left against the cylinder wall.
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(a)
Explain how the cylinder is rotating at a constant speed but at the same time the
riders inside the cylinder are accelerating.
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(3)
(b)
In which direction do the riders accelerate?
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(1)
(c)
What name is given to the resultant force that causes the riders to accelerate?
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(1)
(d)
At the end of the ride the floor goes back into place and the cylinder slows down
and stops.
How does the resultant force on the riders change as the cylinder slows down?
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(1)
(Total 6 marks)
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