Physics 9702 · Paper 2

Waves

Definitions: Waves

One exam question, the mark-scheme answer, and the exact phrases that score (highlighted, then listed below in the same colour).

Exam question

For a progressive wave, state what is meant by displacement.

1 mark

Model answer

Displacement is the distance of a point from its equilibrium position.

Marking points

1 mark each

1distance of a point from its equilibrium position(1)

Exam question

For a progressive wave, state what is meant by the amplitude.

1 mark

Model answer

Amplitude is the maximum displacement from the equilibrium position.

Marking points

1 mark each

1maximum displacement from the equilibrium position(1)

Exam question

For a progressive wave, state what is meant by the period.

1 mark

Model answer

The period is the time for one complete oscillation.

Marking points

1 mark each

1time for one complete oscillation(1)

Exam question

For a progressive wave, state what is meant by the frequency.

1 mark

Model answer

Frequency is the number of oscillations per unit time.

Marking points

1 mark each

1number of oscillations per unit time(1)

Exam question

For a progressive wave, state what is meant by the wavelength.

1 mark

Model answer

Wavelength is the minimum distance between two points in phase.

Marking points

1 mark each

1minimum distance between two points in phase(1)

Exam question

State what is meant by a progressive wave.

1 mark

Model answer

A progressive wave transfers energy from one position to another without transferring matter.

Marking points

1 mark each

1transfers energy from one position to another without transferring matter(1)

Exam question

Distinguish between a transverse wave and a longitudinal wave.

2 marks

Model answer

In a transverse wave the vibrations are at right angles to the direction of energy travel; in a longitudinal wave they are parallel to it.

Marking points

1 mark each

1at right angles to the direction of energy travel(1)
2parallel to it(1)

Exam question

Define the intensity of a wave.

1 mark

Model answer

Intensity is the power per unit area (with $I \propto A^2$ ).

Marking points

1 mark each

1power per unit area(1)

Exam question

State what is meant by a polarised wave, and explain why sound cannot be polarised.

2 marks

Model answer

A polarised wave has vibrations in one plane only. Sound cannot be polarised because it is longitudinal.

Marking points

1 mark each

1one plane only(1)
2longitudinal(1)

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Waves

Definitions: Waves

One exam question, the mark-scheme answer, and the exact phrases that score (highlighted, then listed below in the same colour).

Exam question

For a progressive wave, state what is meant by displacement.

1 mark

Model answer

Displacement is the distance of a point from its equilibrium position.

Marking points

1 mark each

1distance of a point from its equilibrium position(1)

Exam question

For a progressive wave, state what is meant by the amplitude.

1 mark

Model answer

Amplitude is the maximum displacement from the equilibrium position.

Marking points

1 mark each

1maximum displacement from the equilibrium position(1)

Exam question

For a progressive wave, state what is meant by the period.

1 mark

Model answer

The period is the time for one complete oscillation.

Marking points

1 mark each

1time for one complete oscillation(1)

Exam question

For a progressive wave, state what is meant by the frequency.

1 mark

Model answer

Frequency is the number of oscillations per unit time.

Marking points

1 mark each

1number of oscillations per unit time(1)

Exam question

For a progressive wave, state what is meant by the wavelength.

1 mark

Model answer

Wavelength is the minimum distance between two points in phase.

Marking points

1 mark each

1minimum distance between two points in phase(1)

Exam question

State what is meant by a progressive wave.

1 mark

Model answer

A progressive wave transfers energy from one position to another without transferring matter.

Marking points

1 mark each

1transfers energy from one position to another without transferring matter(1)

Exam question

Distinguish between a transverse wave and a longitudinal wave.

2 marks

Model answer

In a transverse wave the vibrations are at right angles to the direction of energy travel; in a longitudinal wave they are parallel to it.

Marking points

1 mark each

1at right angles to the direction of energy travel(1)
2parallel to it(1)

Exam question

Define the intensity of a wave.

1 mark

Model answer

Intensity is the power per unit area (with $I \propto A^2$ ).

Marking points

1 mark each

1power per unit area(1)

Exam question

State what is meant by a polarised wave, and explain why sound cannot be polarised.

2 marks

Model answer

A polarised wave has vibrations in one plane only. Sound cannot be polarised because it is longitudinal.

Marking points

1 mark each

1one plane only(1)
2longitudinal(1)