Mega Deck

Question 1

State what is represented by gravitational field lines.

Answer 1

Gravitational field lines show the direction (and relative magnitude) of force on a mass (placed in the force field)

Question 2

Define the Tesla

Answer 2

The tesla is the strength of the magnetic field/flux density that produces a force of 1 newton in a wire of length 1m with 1 ampere (flowing perpendicular to the field)

Question 3

State what happens to a neutron that is incident on the moderator (1 mark).

Answer 3

The neutron undergoes an elastic collision/bounces off

with less speed/kinetic energy.

Question 4

State what happens to a neutron that is incident on a control rod. (1 mark)

Answer 4

The neutron is absorbed

Question 5

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 (3 marks)

Answer 5

The neutron is absorbed causing the nucleus to split into two smaller daughter nuclei which release several dast moving electrons.

Question 6

How are stationary waves in a microwave? (2 marks)

Answer 6

Waves are reflected (from the oven wall) and interfere with wave travelling in the opposite direction.

Question 7

Explain why most microwave ovens contain a rotating turntable on which the food is placed during cooking. (1 mark)

Answer 7

The position of antinodes/nodes in the food constantly changes.

Question 8

State what is meant by ‘Tensile Stress’

Answer 8

The force exerted per cross-sectional area

Question 9

State what is meant by ‘Tensile Strain’

Answer 9

Extension over original length (ratio)

Question 10

The student increases the frequency of the electromagnetic radiation. Explain the effect this has on the stopping potential. (3 marks)

Answer 10

Stopping potential would be greater
because the energy of the photons (of the
electromagnetic radiation) would be greater.
Therefore, the maximum kinetic energy of electrons would be greater.

Question 11

State what is meant by isotopes. (2 marks)

Answer 11

Atoms with same number of protons but different numbers of neutrons.

Question 12

Explain why two photons are formed instead of a single photon when a helium nucleus annihilates with the anti-helium nucleus. (2 marks)

Answer 12

Momentum must be conserved so need two photons travelling in different directions.

Question 13

State and explain what happens to the ammeter reading when the temperature of the
thermistor increases (2 marks)

Answer 13

At higher temp, resistance of T is lower. So circuit resistance is lower, so ammeter reading increases

Question 14

State what is meant by ionisation. (1 mark)

Answer 14

The removal (or addition) of electrons from (to) an atom or molecule.

Question 15

Use the kinetic theory of gases to explain why the pressure inside a football increases when the temperature of the air inside it rises. Assume that the volume of the ball remains constant. (3 marks)

Answer 15

Ideas of pressure = F/A
Mean KE/rms speed/mean speed of air molecules increases. More collisions with the inside surface of the football each second.

Question 16

Describe two essential features of the orbit needed for the satellite to appear
geostationary. (2 marks)

Answer 16

1. Equatorial orbit
2. Moving west to east
3. Period 24 hours

Question 17

Explain why the current that charges the capacitor falls as the capacitor charges. (3 marks) (connected in parallel)

Answer 17

More charge leads to increased potential difference across the capacitor. V(total) = V(capacitor) + V(resistors). So if V(falls), current falls.

Question 18

Explain what is meant by a capacitance of 4.2 μF. (2 marks)

Answer 18

Ratio of charge to potential, so 4.2μ per volt.