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Physics Unit P2‘Physics for Your Future’

Study and Revision Pack (Higher Paper)

Content Page numberP2 overview and assessment tracking

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Formulae sheet 3P2.1 Specification statements 4P2.1 Exam Questions 5P2.2 Specification statements 16P2.2 Exam Questions 17P2.3 Specification statements 25P2.3 Exam Questions 27P2.4 Specification statements 34P2.4 Exam Questions 36P2.5 Specification statements 43P2.5 Exam Questions 44P2.6 Specification statements 53P2.6 Exam Questions 54

Revision tips in appendix 62

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Overview and assessment trackingPlease use the table below to keep track of your revision. The smarter you work the better results.

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P2.1P2.2P2.3P2.4P2.5P2.6

Use the grade boundaries below as a guide to the grade you are achieving:

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% Grade90 A*80 A70 B60 C50 D

<50 U

P2.1 Specification statementsTo

pic P2 Specification Physics for your future RAG

Cu

rren

t Revised

1 2 3

Topi

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1.1 Be able to describe the structure of the atom, limited to the position, mass and charge of protons, neutrons and electrons1.2 Be able to explain how an insulator can be charged by friction, through the transfer of electrons.1.3 Be able to explain how the material gaining electrons becomes negatively charged and the material losing electrons is left with an equal positive charge.1.4 Know that like charges repel and unlike charges attract.

1.5 Be able to demonstrate an understanding of common electrostatic phenomena in terms of movement of electrons, including:

a) shocks from everyday objectsb) lightningc) attraction by induction such as a charged balloon

attracted to a wall and a charged comb picking up small pieces of paper

1.6 Be able to explain how earthing removes excess charge by movement of electrons.1.7 Be able to explain some of the uses of electrostatic charges in everyday situations, including paint and insecticide sprayers.1.8 Be able to demonstrate an understanding of some of the dangers of electrostatic charges in everyday situations, including fuelling aircraft and tankers together with the use of earthing to prevent the build-up of charge and danger arising.1.9 Know that an electric current is the rate of flow of charge.1.10 Know that the current in metals is a flow of electrons.1.11 Be able to use the equation:charge (coulomb, C) = current (ampere, A) x time (second, s)Q = I x t1.12 Know that cells and batteries supply direct current (d.c.).1.13 Be able to demonstrate an understanding that direct current (d.c.) is movement of charge in one direction only.

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P2.1 Exam Questions- 58 marks, 58 minutes.

Q1.

(a) A lightning strike on a metal tower can be described as follows.

In the cloud.

A thunder cloud contains moving ice particles.Some of these ice particles are negatively charged and some are positively charged.The negatively charged particles move to the bottom of the cloud.

When the charged cloud is over the metal tower.A charge builds up on the top of the metal tower as the cloud passes over.

During the lightning flash.

Eventually a flash of lightning travels between the cloud and the tower. (i) Which row of this table is correct when the cloud is over the top of the tower before the lightning flash?

Put a cross ( ) in the box next to your answer.(1)

charge on top of the cloud is

charge on top of the tower is

A negative negative B negative positive C positive positive D positive negative

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(ii) Here are four statements. Three of these are a reason for what happens at each stage.

Choose the best reason for each of the stages listed below by writing its number in the box next to the description of what happens.

One has been done for you.A reason can only be used once.

(2)

(iii) Explain what happens to the charge on the metal tower as a result of the lightning flash.(2)

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(b) During the lightning flash a total charge of 52 C flows. The average current is 2600 A. Calculate the duration of the flash in seconds.

(3)

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(c) When fuel tanks on an aircraft are being filled, the aircraft, fuel pipes and tanker are connected by a metal wire to the ground.

Explain why this greatly reduces the chance of a spark.(2)

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(Total for Question is 10 marks)Q2.

(a) A student wins a trophy. It is a metal cup on a black plastic base.

The student cleans the trophy.

She holds one of the metal handles and rubs the rest of the trophy with a dry cloth.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer.The plastic base becomes negatively charged because it gains

(1) A atoms B becquerel C einstein D radium

(ii) Explain why the base gains a negative charge when she rubs the trophy with the cloth.(2)

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(iii) The metal cup does not become charged when she rubs the trophy. Suggest why the cup does not become charged.

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(iv) Some dust particles in the air drift near to the plastic base just after she cleans the trophy.

Which diagram shows the correct distribution of charges on a dust particle near to the charged plastic base?


(b) Describe one situation where separation of electric charge can create a spark.(2)

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(Total for Question = 8 marks)

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Q3. Using static electricityWaste gases contain smoke particles.

The diagram shows how smoke particles can be removed from waste gases as they rise through a chimney.

(a) Complete the sentence by putting a cross ( ) in the box next to your answer.

When the smoke particles go through the metal grid they become negatively charged.This is because they

(1) A gain electrons B gain protons C lose electrons D lose protons

(b) When the negatively charged smoke particles move up the chimney, they are attracted to the metal plates.

(i) State why the metal plates attract the smoke particles.(1)

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(ii) State what happens to the charge on the smoke particles when they reach the metal plate.

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(c) There is a current of 1.4 A between the grid and the plates.

(i) Calculate the charge transferred by this current in two minutes. State the unit.

(3)

charge = ........................................ unit ........................................

(ii) The potential difference between the grid and the plate is 400 V.

Calculate the electrical energy transferred in two minutes.

(2)

energy transferred = ....................................... joules


Q4.

A battery sends a current through a metal wire.

(a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer.

Direct current is movement of charge(1)

A backwards and forwards B in many directions C in one direction D up and down

(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.

The particles that flow in the metal wire are(1)

A atoms B electrons C protons D neutrons

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(b) The current in a wire is 3.7 A.

Calculate the charge that flows into the wire in 13 s.(2)

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(c) Plastic is an insulator.

A student rubs a piece of plastic with a cloth.

This gives the plastic a negative charge.

(i) Explain how the plastic is charged by the rubbing.(2)

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(ii) The cloth is also charged when it rubs against the plastic. Describe the charge on the cloth.

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(Total for Question is 8 marks)

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Q5. Electrostatic discharge

(a) Marie works in an office which has a nylon carpet.She walks across the carpet towards her filing cabinet.There is friction between her shoes and the carpet.

When she touches the metal handle of her filing cabinet she feels an electric shock.

(i) State the name of the charged particles which have been transferred between the carpet and her shoes.

(1) ..............................................................................................................................................

(ii) The following sentences explain how Marie got the electric shock.The sentences are in the wrong order.Put them in the correct order by numbering the boxes.

Two have been done for you.(2)

actions order in which the actions happen

Marie walks across the nylon carpet 1charge flows from Marie to the filing cabinetMarie touches the handle 4charge is transferred by friction on to MarieMarie has lost her negative chargea negative charge builds up on Marie

(b) Marie has another filing cabinet which has a black conductive strip at the top.

This black strip helps to prevent electric shocks.This strip has a high resistance but still conducts charge.

If Marie touches the strip before touching the handle she does not feel a shock.Explain, using the idea of electric current, why Marie does not feel a shock.

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*(c) Sparks from electrostatic discharge can sometimes be very dangerous. They can cause a fire or an explosion.

Safety precautions are taken to reduce risks.

Explain how safety precautions, in a particular situation, reduce the risks of fire or explosion.

You may draw a labelled diagram to help with your answer.

(6)

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(Total for Question = 12 marks)13

Q6.(a) Vicky combs her hair with a plastic hair comb. The comb now has a negative charge.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer.

The comb has a negative charge because it has(1)

A gained electrons B lost electrons C gained protons D lost protons

(ii) Vicky's hair has also become charged. Explain how Vicky's hair has become charged.

(2) ..............................................................................................................................................

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(iii) Vicky holds the comb over a small piece of metal foil. The foil jumps up and sticks to the comb.

Show on the diagram where the foil is negatively charged.(1)

(b) Vicky combs her hair with a metal comb. Then she tries to pick up some small pieces of metal foil with the comb. The metal comb does not pick up any pieces of metal foil.

Explain why the metal foil is not picked up by the comb.(2)

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(c) The picture shows an electrostatic paint sprayer about to be used to paint a metal object.

When the paint particles leave the sprayer, they are negatively charged.

Explain the benefits of using this sprayer compared with one that does not charge the paint.(6)

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Revised

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2.1 Be able to describe how an ammeter is placed in series with a component to measure the current, in amps, in the component.

2.2 Be able to explain how current is conserved at a junction.

2.3 Be able to explain how the current in a circuit depends on the potential difference of the source.

2.4 Be able to describe how a voltmeter is placed in parallel with a component to measure the potential difference (voltage), in volts, across it.2.5 HT only: Be able to demonstrate an understanding that potential difference (voltage) is the energy transferred per unit charge passed and hence that the volt is a joule per coulomb.2.6 Revise any investigations on the relationship between potential difference (voltage), current and resistance.

2.7 Be able to explain how changing the resistance in a circuit changes the current and how this can be achieved using a variable resistor

2.8 Be able to use the equation:potential difference (volt, V) = current (ampere, A) x resistance (ohm, Ω)V = I x R2.9 Be able to demonstrate an understanding of how current varies with potential difference for the following devices

a) filament lampsb) diodes

c) fixed resistors

2.10 Be able to demonstrate an understanding of how the resistance of a light- dependent resistor (LDR) changes with light intensity2.11 Be able to demonstrate an understanding of how the resistance of a thermistor changes with change of temperature (negative temperature coefficient thermistors only)

2.12 Be able to explain why, when there is an electric current in a resistor, there is an energy transfer which heats the resistor

2.13 HT only: Be able to explain the energy transfer (in 2.12 above) as the result of collisions between electrons and the ions in the lattice2.14 Be able to distinguish between the advantages and disadvantages of the heating effect of an electric current2.15 Be able to use the equation [appropriate units in ()]:

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P2.2 Exam Questions- 40 marks, 40 minutes

Q7. (a) The diagram shows an electric circuit with two resistors, R and S.

(i) R has a resistance of 11 ohms.Calculate the potential difference across R.

(2)

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(ii) Use information from the diagram to calculate the current in S.(1)

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(iii) Complete the sentence by putting a cross ( ) in the box next to your answer.

A student wants to measure the battery voltage with a voltmeter.

The voltmeter should be placed(1)

A in series with the battery B in parallel with the battery C in parallel with the ammeter D in series with either resistor R or S

(b) Explain why the temperature of a resistor increases when a current passes through it.(2)

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*(c) A resistor is a circuit component. Two other circuit components are a light dependent resistor (LDR) and a thermistor.

Explain how LDRs and thermistors can be used to control the current in a circuit.(6)

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Q8.(a) A designer is going to use a thermistor in a temperature gauge. He connects the thermistor into this circuit.

He heats the thermistor and measures the current at different temperatures. Here are some of the results plotted on a graph.

At 47 °C the current was 0.138 A.

(i) Plot this value on the graph.(1)

(ii) Draw the curve of best fit through the points.(1)

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(iii) The supply voltage is 12 V.

At 20 °C the current is 0.047 A.Calculate the resistance of the thermistor at this temperature.

(3)

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(iv) Use this graph of current against temperature to explain the relationship between resistance and temperature for this thermistor.

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(b) (i) When there is an electric current in a resistor, the resistor gets hot.Explain why the resistor gets hot.

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(ii) Suggest why the thermistor in a temperature gauge might indicate a temperature slightly higher than the actual temperature of its surroundings.

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Q9.

(a) Some students investigate the electrical resistance of different components using this circuit.

(i) Which row of the table is correct for both meters P and Q?


meter P is meter Q is A an ammeter an ammeter B an ammeter a voltmeter C a voltmeter a voltmeter D a voltmeter an ammeter

(ii) One of the components being investigated is a 12 ohm resistor.

When it is in the circuit, the ammeter reading is 0.50 A.

Calculate the voltmeter reading.(2)

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(iii) The students reduce the resistance of the variable resistor.

State what happens to the readings on each of the meters P and Q.(2)

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(iv) The students then reduce the voltage of the power supply. State what happens to the current in the circuit.

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(b) The graphs L, M and N each show how the current in a component varies with the potential difference (voltage) across that component.

Match each graph with the symbol of the component to which it applies. Draw lines to connect each symbol with its correct graph.


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Q10. Using electric current

(a) The photograph shows a device used to measure the amount of light.

The circuit diagram shows how the components inside this device are connected.


The meter used in this circuit is(1)

A a voltmeter connected in series with the LDR B a voltmeter connected in parallel with the LDR C an ammeter connected in series with the LDR D an ammeter connected in parallel with the LDR

(ii) The amount of light entering the light-dependent resistor (LDR) increases.

Which row of the table correctly describes the change in the resistance of the LDR and the change in the current in the circuit?


resistance of the LDR current in circuit

A increases decreasesB increases increasesC decreases decreasesD decreases increases

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(iii) The device is used as a light meter.

It has a 9 V battery.

Calculate the current when the resistance of the LDR is 600Ω.

(3)

current = ........................................ A

(iv) When the light meter has been used for a long time, the meter reading becomes incorrect.Suggest what has happened.

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(b) A different light meter has a diode in its circuit.

(i) Explain what happens when the battery is reversed.(2)

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(ii) Suggest why the manufacturer of the light meter has included a diode.(1)

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P2.3 Specification statements T

opic P2 Specification Physics for your future RAG

Cu

rren

t Revised

1 2 3

Topi

c 3: M

otion

and

For

ces

3.1 Be able to demonstrate an understanding of the following as vector quantities:a) displacementb) velocityc) accelerationd) force3.2 Be able to interpret distance/time graphs including determination of speed from the gradient.3.3 Know that velocity is speed in a stated direction3.4 Be able to use the equation:speed (m/s) = distance (m) / time (s)s = d / t3.5 Be able to use the equation:acceleration (metre per second squared, m/s2) = change in velocity (metre per second, m/s) / time taken (second, s)a = (v - u) / t3.6 Be able to interpret velocity/time graphs to:a) compare acceleration from gradients qualitativelyb) calculate the acceleration from the gradient (for uniform acceleration only)c) determine the distance travelled using the area between the graph line and the time axis (for uniform acceleration only3.7 Be able to draw and interpret a free-body force diagram

3.8 Be able to demonstrate an understanding that when two bodies interact, the forces they exert on each other are equal in size and opposite in direction and that these are known as action and reaction forces3.9 Be able to calculate a resultant force using a range of forces (limited to the resultant of forces acting along a line) including resistive forces

3.10 Be able to demonstrate an understanding that if the resultant force acting on a body is zero, it will remain at rest or continue to move at the same velocity3.11 Be able to demonstrate an understanding that if the resultant force acting on a body is not zero, it will accelerate in the direction of the resultant force3.12 Be able to demonstrate an understanding that a resultant

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force acting on an object produces an acceleration which depends on:a) the size of the resultant forceb) the mass of the object3.13 Be able to use the equation:force (newton, N) = mass (kilogram, kg) x acceleration (metre per second squared, m/s2)F = m x a3.14 Be able to use the equation:weight (newton, N) = mass (kilogram, kg) x gravitational field strength (newton per kilogram, N/kg)W = m x g3.15 Revise any investigations on the relationship between force, mass and acceleration

3.16 Know that in a vacuum all falling bodies accelerate at the same rate

3.17 Be able to demonstrate an understanding that:

a) when an object falls through an atmosphere air resistance increases with increasing speed

b) air resistance increases until it is equal in size to the weight of the falling object

c) when the two forces are balanced, acceleration is zero and terminal velocity is reached

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P2.3 Exam Questions- 41 marks, 41 minutes.

Q11. (a) A car is travelling along a level road.


When the velocity of the car is constant, the force of friction on it is(1)

A zero B greater than the driving force C smaller than the driving force D the same size as the driving force

(ii) The car now accelerates in a straight line. Its average acceleration is 12 m/s2.

Calculate the increase in velocity of the car in 4.0 s.(3)

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(b) This table shows data about two other cars.

The owner of the family car claims that although the sports car has greater acceleration, it produces a smaller accelerating force than his family car.Explain how these figures support his claim.

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*(c) After going to the shops, a car driver places a bag of shopping on the passenger seat.

During the journey home, the driver has to use the brakes to stop very suddenly. The driver is wearing a seat belt.

Explain what happens next to the car, the driver and the shopping bag.(6)

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Q12.

A water tank drips water.

(a) Scientists could use four quantities to describe the movement of the water drops. Three of these quantities are vectors.

The other quantity is a scalar.

acceleration force mass velocity


The scalar quantity is(1)

A acceleration B force C mass D velocity

(ii) Complete the following sentence using one of the quantities from the word box above.(1)

In a vacuum, all bodies falling towards the Earth's surface have the same . . . . . . . . . . . . . . . . . . . . . . .

(b) The mass of one water drop is 0.000 08 kg.

Calculate its weight.

(gravitational field strength is 10 N/kg)(2)

weight = . . . . . . . . . . . . . . . . . . . . . . N

(c) The water drop falls to the ground, 13 m below, in 1.7 s. Calculate the average speed of the drop while it is falling.

(2)

average speed = . . . . . . . . . . . . . . . . . . . . . . m/s

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*(d) The tank is a long way above the ground. It drips at a steady rate.

The first drawing shows water drops which have just left the tank.The second drawing shows water drops which are near to the ground.

Explain why the drops which are near to the ground are an equal distance apart but the drops which have just started to fall are not.

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(Total for Question is 12 marks)30

Q13.Forces and motionThe graph shows a velocity-time graph for a cyclist over a time of 60 s.

(a) (i) When is the cyclist travelling with greatest velocity?


A for the first 15 seconds B between 15 and 40 seconds C between 40 and 50 seconds D for the last 10 seconds

(ii) Calculate how long the cyclist is stationary for.

(1)

answer = .................................... seconds

(b) The cyclist in this picture is travelling at a constant velocity.

Her muscles produce a driving force of 15 N.

Draw an arrow on the diagram to show the size and direction of the overall resistive force acting on the cyclist.

(1)

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(c) The cyclist accelerates at 1.4 m/s2.

The mass of the cyclist and bicycle is 60 kg.

(i) Calculate the resultant force.

(2)

resultant force = ....................................... N

(ii) The cyclist accelerates for 8 s.

Calculate the increase in velocity during this time.

(3)

increase in velocity = ............................... m/s


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Q14.The graph shows how the velocity of a small car changes with time.


The resultant force on the car will be zero when the car is(1)

A accelerating B decelerating C changing velocity D moving at a constant velocity

(b) (i) Use the graph to estimate the velocity of the car at three seconds.(1)

..............................................................................................................................................(ii) Calculate the acceleration of the car when it is speeding up.

(2)

acceleration = . . . . . . . . . . . . . . . . . . . . . . m/s2

(iii) Explain why the units of acceleration are m/s2.(2)

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(iv) Show that the car travels further at a constant velocity than it does when it is slowing down.(3)

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Cu

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4.1 Know that the stopping distance of a vehicle is made up of the sum of the thinking distance and the braking distance

4.2 Be able to demonstrate an understanding of the factors affecting the stopping distance of a vehicle, including:a) the mass of the vehicleb) the speed of the vehiclec) the driver’s reaction timed) the state of the vehicle’s brakese) the state of the roadf) the amount of friction between the tyre and the road surface4.3 Revise any investigations on the forces required to slide blocks along different surfaces, with differing amounts of friction4.4 Be able to use the equation:momentum (kilogram metre per second, kg m/s) = mass (kilogram, kg) x velocity (metre per second, m/s)to calculate the momentum of a moving objectmomentum = mass x velocitymomentum = mv4.5 Be able to demonstrate an understanding of momentum as a vector quantity4.6 Be able to demonstrate an understanding of the idea of linear momentum conservation4.7 Be able to demonstrate an understanding of the idea of rate of change of momentum to explain protective features including bubble wraps, seat belts, crumple zones and air bags4.8 Revise any investigations on how crumple zones can be used to reduce the forces in collisions4.9 HT only: Be able to use the equation:force (newton, N) = change in momentum (kilogram metre per second, kg m/s) / time (second, s)F = (mv - mu) / tto calculate the change in momentum of a system, as in 4.64.10 Be able to use the equation:work done (joule, J) = force (newton, N) x distance moved in

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the direction of the force (metre, m)E = F x d4.11 Be able to demonstrate an understanding that energy transferred (joule, J) is equal to work done (joule, J)4.12 Know that power is the rate of doing work and is measured in watts, W4.13 Be able to use the equation:power (watt, W) = work done (joule, J) / time taken (second, s)P = E / t4.14 Know that one watt is equal to one joule per second, J/s4.15 Be able to use the equation:gravitational potential energy (joule, J) = mass (kilogram, kg) x gravitational field strength (newton per kilogram, N/kg) x vertical height (metre, m)GPE = m x g x h4.16 Be able to use the equation:kinetic energy (joule, J) = 1/2 mass (kilogram, kg) x velocity2 ((metre/second)2, (m/s)2)KE = 1/2mv2

4.17 Be able to demonstrate an understanding of the idea of conservation of energy in various energy transfers4.18 HT only: Be able to carry out calculations on work done to show the dependence of braking distance for a vehicle on initial velocity squared (work done to bring a vehicle to rest equals its initial kinetic energy).

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P2.4 Exam questions – 41 marks, 41 minutes.

Q15. A 60 kg student weighs 600 N.He does a bungee jump.

The bungee cord becomes straight and starts to stretch when he has fallen 50 m.

(a) Complete the sentence by putting a cross ( ) in the box next to your answer. He first stops moving

(1) A before all the energy has disappeared B before the bungee cord starts to stretch C when the bungee cord is stretched the most D when the elastic potential energy is zero

(b) Complete the sentence by putting a cross ( ) in the box next to your answer.

When his speed is 10 m/s his momentum is(1)

A 600 kg m/s B 3 000 kg m/s C 6 000 N m/s D 30 000 N m/s

(c) (i) Calculate the change in gravitational potential energy as the student falls 50 m.Give the unit.

(3)

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(ii) State at what point in the bungee jump the student has maximum kinetic energy.(1)

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(iii) Explain why his maximum kinetic energy is likely to be less than your answer to (c)(i).(2)

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(Total for Question = 8 marks)Q16.Andrew skis down a hill.

(a) Andrew starts from the top of the hill and his speed increases as he goes downhill.He controls his speed and direction by using his skis.He brings himself to a stop at the bottom of the hill.

Describe the energy changes that happen between starting and stopping.(3)

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(b) Andrew returns to the top of the hill and starts again.(i) His mass is 67 kg.

Show that his momentum is about 2000 kg m/s when his velocity is 31 m/s.(2)

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(ii) He falls over when his momentum is 2000 kg m/s.

After he falls over, he slows down by sliding across the snow.It takes 2.3 s for his momentum to reduce to zero.

Calculate the average force on Andrew as he slows down.(2)

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(iii) Andrew is not injured by the fall even though he was moving quickly. Use ideas about force and momentum to explain why he is not injured.

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Q17. Momentum, energy and forcesA box with a mass of 0.8 kg is lifted from the floor and placed on a shelf.

The shelf is 1.8 m above the floor.

(a) (i) The box has gained gravitational potential energy.

Calculate the gain in gravitational potential energy.Gravitational field strength = 10 N/kg

(2)

gain in gravitational potential energy = ......................................... J

(ii) The box falls off the shelf.

State the kinetic energy of the box just before it hits the floor.(1)

....................................................................... J

(iii) Just before the box hits the floor it has a momentum of 4.8 kg m/s.

Calculate the velocity of the box just before it hits the floor.(3)

velocity = ........................................ m/s

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*(b) The items in the box are packed in bubble wrap to protect them from damage.

Explain, by considering changes either in momentum or in kinetic energy, how bubble wrap protects the items in a box from damage caused by a fall.

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Q18.A child is stationary on a swing.

(a) The child is given a push by his brother to start him swinging. His brother applies a steady force of 84 N over a distance of 0.25 m.

(i) Calculate the work done by this force.

(2)

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(ii) State how much energy is transferred by this force.

(1) ..............................................................................................................................................

(iii) After several more pushes, the child has a kinetic energy of 71 J. The mass of the child is 27 kg. Show that the velocity of the child at this point is about 2.3 m/s.

(2)(iv) Which one of these quantities changes in both size and direction while he is swinging? Put a cross ( ) in the box next to your answer.

(1) A his gravitational potential energy B his momentum C the force of gravity acting on him D his kinetic energy

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*(b) The brother then stops pushing the child. The graph shows how the kinetic energy of the child varies over the next few swings.

Explain the energy changes during this time.(6)

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Revised

1 2 3

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c 5: N

ucle

ar F

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5.1 Be able to describe the structure of nuclei of isotopes using the terms atomic (proton) number and mass (nucleon) number and using symbols in the format 14

6C

5.2 Be able to explain how atoms may gain or lose electrons to form ions.

5.3 Know that alpha and beta particles and gamma rays are ionising radiations emitted from unstable nuclei in a random process.5.4 Know that an alpha particle is equivalent to a helium nucleus, a beta particle is an electron emitted from the nucleus and a gamma ray is electromagnetic radiation5.5 Be able to compare alpha, beta and gamma radiations in terms of their abilities to penetrate and ionise.5.6 Be able to demonstrate an understanding that nuclear reactions can be a source of energy, including fission, fusion and radioactive decay.5.7 Be able to explain how the fission of U-235 produces two daughter nuclei and two or more neutrons, accompanied by a release of energy.5.8 Be able to explain the principle of a controlled nuclear chain reaction.

5.9 Be able to explain how the chain reaction is controlled in a nuclear reactor including the action of moderators and control rods.

5.10 Be able to describe how thermal (heat) energy from the chain reaction is converted into electrical energy in a nuclear power station.

5.11 Know that the products of nuclear fission are radioactive.

5.12 Be able to describe nuclear fusion as the creation of larger nuclei from smaller nuclei, accompanied by a release of energy and recognise fusion as the energy source for stars.5.13 Be able to explain the difference between nuclear fusion and nuclear fission.5.14 HT only: Be able to explain why nuclear fusion does not happen at low temperatures and pressures, due to electrostatic repulsion of protons.5.15 HT only: Be able to relate the conditions for fusion to the difficulty of making a practical and economic form of power station.5.16 Be able to demonstrate an understanding that new scientific theories, such as ‘cold fusion’, are not accepted until they have been validated by the scientific community.

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P2.5 Exam Questions – 43 marks, 43 minutes.

Q19. Alpha, beta and gamma are types of ionising radiation.

(a) State two ways in which gamma radiation is different from alpha radiation.(2)

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(b) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. A beta particle is emitted by

(1) A an alpha particle B a fusion particle C a gamma ray D an unstable nucleus

(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.

A beta particle has an identical charge to(1)

A an alpha particle B an electron C a neutron D a nucleus

(c) Explain how an atom becomes ionised by radiation.(2)

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*(d) The removable lens of this old camera has four pieces of glass in it.

One of the pieces of glass is radioactive. Its surface is covered with a thin layer of magnesium fluoride.

Radioactive isotopes in the glass emit alpha, beta and gamma radiation in all directions.A scientist removes the lens from the camera. She measures the radiation coming from the back, front and side of the lens.

The amount of radiation is different in each direction.

No alpha radiation is detected.

The readings are shown on the diagram.

Explain why the readings in the three directions are different.(6)

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Q20.(a) Two isotopes of uranium are U-235 and U-238.

Here are the symbols of the nuclei of these isotopes.


The U-235 isotope has(1)

A the same number of neutrons as U-238 B the same number of protons as U-238 C more neutrons than U-238 D more protons than U-238

(ii) U-235 is radioactive.

When it decays, it releases an alpha particle.

Describe an alpha particle.(2)

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(b) U-235 can also be made to undergo fission. Describe what happens during nuclear fission.

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(c) Fission is used in nuclear reactors. Graphite is used as a moderator in nuclear reactors. Explain why a moderator is needed in a nuclear reactor.

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Q21. Nuclear reactions


Two types of nuclear reaction are nuclear fission and nuclear fusion.

Nuclear fission and nuclear fusion reactions both(1)

A combine hydrogen nuclei B combine uranium nuclei C release neutrons D release energy

(b) In 1989, two scientists called Pons and Fleischmann claimed to have produced ‘cold fusion’.

Their claim has never been validated by the scientific community.

Explain the phrase validated by the scientific community.(2)

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(c) Nuclear fusion is the main energy source for stars.Describe what happens in nuclear fusion.

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*(d) Describe how the nuclear fission of uranium-235 is used to produce electricity in a nuclear power station.

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Q22.

Uranium-238 is an isotope of uranium. It may undergo either radioactive decay or nuclear fission.A nucleus of uranium-238 is shown as Q in the chart.

(a) State two letters from the chart which show isotopes of the same element.(1)

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(b) Explain what happens when Q decays to P.(2)

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(c) Explain what happens when P decays to O.(2)

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(d) Particles released during radioactive decay can have different energies. A suitable unit for these energies is MeV. For one type of decay, the particles released have energies between 4.0 MeV and 10.0 MeV.

The graph shows how far the particles with these energies travel in air.

(i) State the name of this type of particle.(1)

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(ii) Use information from the graph to describe how the distance travelled in air depends on the energy of the particle.

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(e) Uranium-238 can only undergo nuclear fission by absorbing fast neutrons. The fission emits neutrons which very quickly lose their energy.

Suggest why the fission of uranium-238 does not produce a chain reaction.(2)

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P2.6 Specification statements To


Cu

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t Revised

1 2 3

Top

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anta

ges a

nd d

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6.1 Be able to explain what is meant by background radiation, including how regional variations within the UK are caused in particular by radon gas.6.2 Know the origins of background radiation from Earth and space.6.3 Be able to describe uses of radioactivity, including:a) household fire (smoke) alarmsb) irradiating foodc) sterilisation of equipmentd) tracing and gauging thicknessese) diagnosis and treatment of cancer6.4 Be able to describe how the activity of a radioactive source decreases over a period of time.6.5 Know that the unit of activity of a radioactive isotope is the Becquerel, Bq.6.6 Know that the half-life of a radioactive isotope is the time taken for half the undecayed nuclei to decay.6.7 Be able to use the concept of half-life to carry out simple calculations on the decay of a radioactive isotope, including graphical representations.6.8 Revise any investigations on models which simulate radioactive decay.6.9 Be able to demonstrate an understanding of the dangers of ionising radiation in terms of tissue damage and possible mutations and relate this to the precautions needed.6.10 Be able to describe how scientists have changed their ideas of radioactivity over time, including:a) the awareness of the hazards associated with radioactive sourcesb) why the scientific ideas change over time6.11 Be able to discuss the long-term possibilities for storage and disposal of nuclear waste.6.12 Be able to evaluate the advantages and disadvantages of nuclear power for generating electricity, including the lack of carbon dioxide emissions, risks, public perception, waste disposal and safety issues.

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P2.6 Exam Questions – 41 marks, 41 minutes.

Q23.

Carbon-14 is a radioactive isotope that occurs naturally.

Scientists use carbon-14 to help find the age of old pieces of wood.This technique is called carbon dating.

It uses the idea of half-life.

(a) Which of these describes half-life?


A the time it takes for half of the undecayed nuclei to decay B the time it takes for all of the undecayed nuclei to decay C half the time it takes for all of the undecayed nuclei to decay D half the time it takes for half of the undecayed nuclei to decay

(b) Sketch a graph to show how the activity of a radioactive isotope changes with time. Use the axes below. Start your line from point P.

(3)

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(c) A scientist investigates an old wooden comb.

The activity of the carbon-14 in it is 0.55 Bq.The estimated age of the comb is 11 400 years.

The half-life of carbon-14 is 5700 years.

(i) Calculate the activity of the carbon-14 in the comb when it was new.(3)

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(ii) The scientist takes several readings of background radiation. Explain why this is necessary to improve the accuracy of the investigation.

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(iii) Old objects like the comb emit a very small amount of radiation. The activity from the comb is about the same as comes from background radiation.Scientists have stopped measuring the activity of carbon-14 for carbon dating.Instead, they can measure the mass of undecayed carbon-14 left in the sample.

Suggest a reason for this change.(1)

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Q24.

(a) A scientist uses a Geiger counter to measure the radioactivity of a sample.

She writes down the results in her notebook.

The Geiger counter gives a count rate of 120 counts per minute.The average background radiation in her laboratory is 10 counts per minute.

(i) What should she write down for the count rate of this sample?


A 12 counts per minute B 110 counts per minute C 130 counts per minute D 1200 counts per minute

(ii) Name one source of background radiation.(1)

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(iii) Explain why some people are exposed to more background radiation than others.(2)

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(iv) Complete the sentence by putting a cross ( ) in the box next to your answer. The recommended safe limit for exposure to radiation has been reduced over the last 80 years.

This is because now(1)

A better instruments allow scientists to make measurements more quickly B global warming has increased the rate of decay of radioactive materials C humans release more radioactive materials into the environment D scientists have a better understanding of the dangers of radiation

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(b) After the accident at the Fukushima nuclear plant in Japan, some drinking water became contaminated with radioactive iodine-131.

The graph shows how the activity of a sample of iodine-131 changes over two weeks.

(i) Use the graph to estimate the half-life of the iodine-131. Show your working clearly.

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..............................................................................................................................................(ii) The recommended safe limit for a sample of this size is 100 Bq. How long did it take for the activity of the sample to decay until it was below the safe limit?

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(iii) When iodine-131 decays, it emits beta radiation. State one possible danger to health from exposure to beta radiation.

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Q25. Radioactivity, its uses and problems

(a) Radioactivity is used in medicine to diagnose and treat cancer.State two other uses of radioactivity.

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(b) Which of these is the correct definition for the half-life of a radioactive isotope?


A it is the time it takes for half of an atom to decay B it is the number of atoms left when half have decayed C it is the time taken for half the undecayed nuclei to decay D it is half of the time it takes for all the undecayed nuclei to decay

(c) (i) Iodine-131 emits beta particles.State what a beta particle is.

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(ii) The graph shows how the activity of iodine-131 varies with time.

A sample of iodine-131 has a mass of 100 mg.How much iodine-131 will remain after 24 days?

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(d) Scientists in Finland are building a facility for the storage of radioactive waste.They plan to bury radioactive waste deep underground.Describe some of the issues that need to be considered when planning to bury nuclear waste.

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Q26.

(a) An underground oil pipe starts to leak oil.To find the leak, a technician adds a gamma source to the oil flowing in the pipe.

Describe how the technician can find the position of the leak.(2)

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(b) Which of these is correct for half-life?


A It is half the time for all the atoms to decay B It is the time it takes for an atom to half decay C It is the time it takes for half an atom to decay D It is the time it takes for half the atoms to decay

(c) The graph shows how the activity of a sample of a radioactive material changes with time. The sample has an initial activity of 80 counts per minute.

(i) Use the graph to find the half-life of the material.(1)

.............................................................................................................................................. (ii) Another sample of the material has an initial count rate of 40 counts per minute.

Sketch, on the same axes, the activity of this sample for the first 4 days.(2)

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*(d) Some scientists carry out an experiment to measure the radioactivity from a source to be used in a factory.

They measure the background radiation before and after their experiment.They take the background count at the same place as they do their experiment.

Explain how this procedure helps to make sure that the results of the experiment are valid.(6)

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Top ten tips

Tip 1: Plan your revision

Create a realistic and well-presented timetable which you will adhere to. Include exam dates and deadlines for coursework. Add in sports/social/family commitments. Show it to your parents; get them to add in dates you might not know about.

If you have a block of exams, plan for them. If you have three exams in three days, you will need to be prepared to walk into the last exam before you walk into the first. For block exams create one page revision reminder notes which allow you to review the whole course in a short space of time.

Give priority to the exams which are worth the most to you, or you need to spend the most time on.

Tip 2: get a revision guide for your course

Tip 3: print off all the past papers AND mark schemes possible. Use half the papers during revision, and half to test your knowledge throughout.

Tip 4: Contact your teacher so they can help when you get stuck (a lot)

Tip 5: get the right environment:

o no distractions (no music, Facebook, tv, family and friends)o not too hot (cold temperature keeps your body awake open a window if necessary)o comfortableo space or organisation (don’t get your papers all muddled up)o paper to write noteso pens/pencils

Tip 6: Segment your revision of a subject. Don’t try to revise all of the subject at once. Select one section, revise it, learn it, and find all the questions you can on that knowledge to test it.

Tip 7: Revise smart. Don't revise for more than your brain can cope with. You need to be aware of when it has stopped going in. I always found around 40-50 mins hard-core revision was the most useful time. Then take short useful breaks, use a different part of your brain, try doing something physical (don’t get onto blackops as you won’t get off it again). Take 10 minute breaks.

Tip 8: Nap!, believe it or not, you will boost the amount you can learn in one day by 30%+ just by taking short naps (10-20 mins). Set an alarm though! This is because what you have learnt goes from your long term to your short term memory

Tip 9: Don't think you know it, test it. Doing questions is the only way of testing your application of knowledge. This is easier in some subjects than others. Science and Maths there is no excuse for not doing loads of practise questions. Mark those questions using answers, check you have answer before even attempting questions as it will be useless otherwise.

Tip 10: follow my previous nine tips

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web viewuse the grade boundaries below as a guide to the grade you are achieving: %

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