Practice Topic C - Wave behaviour with authentic IB Physics exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like mechanics, thermodynamics, and waves. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
The diagram shows a standing wave formed on a string with both ends fixed. Points A and B are marked. Point B lies at a point of zero displacement, and point A lies at a point of maximum displacement.

Identify whether points A and B are nodes or antinodes.
State the condition for the formation of a standing wave on a string.
Determine the wavelength of the wave if the length of the string is .
Outline how this standing wave is produced by two traveling waves.
A spacecraft moves directly toward a space station at and emits a radio signal with a rest frequency of . The frequency of the signal received by the space station is approximately .
Determine the observed wavelength of the signal on the space station.
Explain why the relativistic formula must be used instead of the classical one.
The diagram shows a stationary observer while a loudspeaker moves toward them, emitting a constant sound. The observer hears a change in the pitch of the sound due to the relative motion of the source.

State what happens to the frequency of the sound as heard by the observer.
Outline why this change in frequency occurs.
Suggest what would be heard if the source were moving away from the observer instead.
Describe one real-life situation in which this Doppler effect can be experienced.
The diagram shows a loudspeaker moving away from a stationary observer. The loudspeaker emits a constant tone, but the observer hears a change in the sound due to the Doppler effect.

State what happens to the frequency of the sound as heard by the observer.
Outline why this change in frequency occurs.
Suggest what would happen to the pitch of the sound if the source stopped moving.
Describe one real-life situation where a similar Doppler effect can be observed.
The graph shows the displacement-time representation of two transverse waves (solid and dashed) travelling through the same medium. Both waves have the same amplitude and frequency.

State the amplitude of either wave.
Determine the period of the waves.
Determine the phase difference between the two waves.
Outline one difference between the two waves other than phase.
Explain how the graph supports the principle of superposition.
A stationary ambulance emits a siren at a frequency of . An observer stands some distance in front of the ambulance.
State what is meant by the Doppler effect.
Calculate the observed frequency if the ambulance moves toward the observer at and the speed of sound is .
Explain whether the observed frequency would be higher or lower if the observer were moving toward the ambulance.
Two waves of equal amplitude and frequency travel in opposite directions along a string fixed at both ends.
Explain how a standing wave is formed.
Describe the difference between nodes and antinodes in a standing wave.
A standing wave with three antinodes forms on a string of length . Calculate the wavelength of the wave.
The wave has a frequency of . Determine the speed of the wave on the string.
Sketch the wave pattern on the string, labeling all nodes and antinodes.
A ripple tank is used to demonstrate wave behaviour. Straight water waves are directed towards a barrier with a small gap in it.
Describe the diffraction pattern observed when the gap width is smaller than the wavelength of the incident waves.
Suggest how the diffraction pattern changes as the gap becomes significantly wider than the wavelength.
Explain how the degree of diffraction depends on the relationship between wavelength and gap width.
State one similarity and one difference between diffraction of light and water waves.
Discuss how diffraction experiments provide evidence for the wave model of light.
The graph shows the transverse displacement in millimetres of points on a stretched string as a function of distance in metres along the string at a fixed instant in time.

State the amplitude of the wave.
State the wavelength of the wave.
The wave has a frequency of . Calculate the speed of the wave.
Identify whether this is a transverse or longitudinal wave. Justify your answer.