A Level Paper 2 Past Paper Errors

Question 1

What happens to a neutron that is incident on a moderator

Answer 1

Neutron undergoes elastic collision with moderator
It bounces off and loses kinetic energy and speed

Question 2

A slow-moving neutron is in collision with a nucleus of an atom of the fuel which causes fission. Describe what happens in the process

Answer 2

Neutron is absorbed
Causing nucleus of fuel to split into two smaller nuclei
Releasing fast-moving neutrons

Question 3

Answer 3

Question 4

Answer 4

Paper - no drop so there is no alpha as alpha gets blocked by Paper and does not pass through, hence no alpha present
Aluminium foil - big drop some is blocked so beta is likely present
Thick steel - still some gets through likely gamma

Question 5

Answer 5

Question 6

What is meant by specific latent heat of fusion

Answer 6

Energy required per kg of material to change state from the solid state to its liquid state without changing the temperature

Question 7

The Pump can circulate the water at different speeds. When working at higher speeds the rise in temperature is greater. Explain why, assuming no heat is transferred to the surroundings

Answer 7

When the pump is working at a speed, the pump is doing work on the water
- as pump increases randomness
- mean speed is proportional to the absolute temperature

Question 8

Define the electric field strength at a point in an electric field

Answer 8

Force per unit charge
On a small positive test charge at that point

Question 9

Answer 9

Question 10

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Suggest with a reason, which type of radiation is likely to be the most appropriate for the sertilisation of metallic surgical instruments

Answer 13

Gamma radiation because it is the most penetrating

Question 14

Explain why the public need not to worry that irradicated surgical instruments become radioactive once sterilised

Answer 14

To become radioactive, the nucleus has to be affected which ionising radiation does not do
Only outer electrons affected by ionising radiation and not nucleus

Question 15

State two possible reasons why the results do not follow th expected inverse-square law

Answer 15

Question 16

Answer 16

Question 17

Decay constant = 1.42 x 10^-11 years^-1

Answer 17

Question 18

Answer 18

Question 19

Why could having more neutrons lead to an isotope being more stable

Answer 19

Having fewer protons reduces repulsion so increases stability

Question 20

Answer 20

Question 21

Answer 21

Question 22

Answer 22

B

Question 23

Answer 23

Question 24

Answer 24

C

Question 25

Answer 25

Question 26

Answer 26

C

Question 27

Answer 27

B

Question 28

Answer 28

Magnetic force is always perpendicular (90 degrees) to the velocity, hence there is no work done So energy remains the same and so kinetic energy remains the same Hence velocity stays the same Answer is C

Question 29

Answer 29

Use of left hand rule As force is constantly acting outwards, it causes an increase of diameter of the coil Answer is C

Question 30

Answer 30

Question 31

Answer 31

Question 32

Answer 32

Question 33

Answer 33

Question 34

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Question 35

Stud nts measures theta at 7 degrees. Discuss whether measurement is consistent with other data in investigation. Electromagnetic force = 4 x 10^-3 N

Answer 35

Question 36

For 5.3) flux density = 2.5 x 10^-2 T, area = 5 x 10^-4

Answer 36

Question 37

Answer 37

Question 38

Answer 38

Question 39

Answer 39

Question 40

Answer 40

Question 41

Answer 41

Electric Field lines show direction a positive charge would move An electron which is negatively charged, feels a force in the opposite direction Answer is D

Question 42

Answer 42

For count rate, it must be detected and to be detected it must stop when it meets object Alpha present due to straight tracks about 4cm of length, and count rate is detected so alpha present Count detected 10cm away, beta or gamma present A 5 mm sheet of aluminium stops all counts so no gamma present and only beta as beta gets stopped by aluminium D is correct answer

Question 43

Answer 43

B

Question 44

a) explain how energy tranferred to the sample changes the arrangement of atoms during the time interval ta to tb b) Describe how motion of atoms change from tb to tc

Answer 44

a) energy tranferred reduces number of atomic neighbors b) mean speed/ mean kinetic energy increases

Question 45

Sample has mass of 0.25kg. Determine specific heat capacity of M when In the liquid state. State an appropriate SI unit for your answer

Answer 45

Question 46

A spring mechanism can project an object vertically to a maximum height of 1.0 m from the surface of the earth. Determine whether the same mechanism could project the same object vertically to a maximum height greater than 100 metres when placed on the surface of Ariel

Answer 46

Question 47

Answer 47

Question 48

Only complete 4.3, data from 4.1 needed

Answer 48

Question 49

State and explain a change to one control, setting in the oscilloscope that would reduce the uncertainty

Answer 49

Reduce time-base setting Uncertainty is due to smallness of divisions and this action means waveform is strecthed in the x direction Increase y-gain Uncertainty is due to smallness of divisions and this action means trace is strecthed vertically in the y-direction

Question 50

Only 5.2 & 5.3

Answer 50

5.3)Particle 5 or 6 Cannot be particle's 1,2 or 3 because these particles deflect up Cannot be 4 as this would backscatter Cannot be 7,8 or 9 because deflection would be too small

Question 51

All nuclei have the same approximate density. State one conclusion about nucleons in a nucleus that can be deduced from this fact

Answer 51

Neutrons and protons have similar volumes Neutrons and protons have similar masses Nucleons have constant seperation

Question 52

Answer 52

Question 53

Mass of U-238 is 1.4kg

Answer 53

Question 54

Answer 54

Question 55

Answer 55

Question 56

Answer 56

Question 57

Answer 57

Question 58

Answer 58

Question 59

Answer 59

C

Question 60

Explain what is meant by a dielectric constant of 6.0

Answer 60

The permitivity of the dielectric is 6 times the permitivity of free space

Question 61

Explain how polar molecules cause a change in capacitance

Answer 61

Polar molecules allign their positive side facing the negative plate Reducing the field between the plates The pd reduces between the plates but the charge remains the same, hence the capacitance increases

Question 62

Why does launching a satellite from the equator minimise the amount of fuel required

Answer 62

At this point the satellite has the largest initial kinetic energy/speed from the Earth's rotation

Question 63

Equation for gravitational potential energy

Answer 63

- GMm / r

Question 64

Answer 64

Question 65

Gas molecule has 500 Crms. Molar mass of gas is 0.209. calculate temperature of the gas

Answer 65

Question 66

Coil is now moved at a constant speed along the x-axis so that x is increasing. An emf is induced across the terminals of the search coil. Explain what happens to the emf as the search coil moves

Answer 66

Question 67

The search coil passes through the position where x=0.1 metres. Deduce whether the emf can exceed 5mV for values of x greater than 0.1 metre

Answer 67

Question 68

Explain why protons travel in a semi-circular path in a dee

Answer 68

Force due to the uniform magnetic field is constant and at 90 degrees to the direction of travel The force is the centripetal force for the motion of the proton

Question 69

Answer 69

Question 70

In kinetic energy equation, e= charge of proton mp= mass of proton B = magnetic flux R = radius

Answer 70

Question 71

Explain in terms of binding energy why energy can be released when two nuclei undergo nuclear fusion

Answer 71

Total mass of nuclei is more than than mass of fusion product Binding energy per nucleon increaes when a nucleon is formed by fission

Question 72

Answer 72

Question 73

Answer 73

Question 74

Answer 74

B

Question 75

Answer 75

Question 76

Answer 76

Question 77

Answer 77

Question 78

Answer 78

A Only third option works About YY'

Question 79

Answer 79

Question 80

Answer 80

Question 81

Question 82

Answer 82

Question 83

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Question 84

Answer 84

Question 85

Answer 85

Question 86

Electrons are tranferred to a spehere, state the location of these excess electrons

Answer 86

Excess electrons are located on the outer surface Excess elecectrons are equally spaced because electrons mutually repel

Question 87

SI unit for Electric Field strength

Answer 87

V m^-1 N C^-1

Question 88

Answer 88

Question 89

R Is the radius of a planet

Answer 89

Question 90

Answer 90

Question 91

Answer 91

Question 92

Answer 92

Question 93

State what is meant by binding energy of a nucleus

Answer 93

Question 94

Answer 94

Question 95

Answer 95

Question 96

Answer 96

Question 97

Answer 97

Question 98

Answer 98

C

Question 99

State what is meant by internal energy of an ideal gas

Answer 99

Total kinetic energy of particles

Question 100

Show that frequency of collisions is c/2L

Answer 100

Question 101

Deduce an expression in terms of m,c and V to represent pressure exerted on W. Refer to Newtons Laws of motion

Answer 101

Question 102

Answer 102

Question 103

Answer 103

Question 104

Answer 104

Question 105

Answer 105

Question 106

Answer 106

Question 107

Answer 107

Question 108

In practise air motion does not affect speed of electron or argon ion. State how motions of these two would be different if air resistance played a part

Answer 108

Due to collisions Argon loses more energy/speed compared to electrons as argon is more ionising than electrons

Question 109

Answer 109

Question 110

Answer 110

Question 111

In simple terms how would you calculate area of this graph

Answer 111

Question 112

Answer 112

Question 113

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Question 114

Answer 114

Question 115

Another material commonly used as moderator apart from graphite

Answer 115

Water

Question 116

Answer 116

Question 117

Explain with reference to figure 15, why elements with a small nucleon number are preferred as moderators

Answer 117

Question 118

Answer 118

Question 119

Answer 119

B

Question 120

Answer 120

A

Question 121

Answer 121

Question 122

Answer 122

D

Question 123

Answer 123

A

Question 124

Answer 124

B

Question 126

Answer 126

Question 127

Answer 127

Question 128

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Question 129

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Question 130

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Question 131

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Question 132

Answer 132

Question 133

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Question 134

Answer 134

Question 135

Skip 6.2 and 6.3

Answer 135

Question 136

Answer 136

Question 137

Answer 137

Question 138

Answer 138

Question 139

Answer 139

Question 140

Answer 140

D

Question 141

Answer 141

B

Question 142

Answer 142

B

Question 143

Answer 143