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 block of mass is attached to a spring with a spring constant and oscillates on a frictionless surface. The maximum displacement from equilibrium is .
Calculate the angular frequency of the motion.
Determine the maximum speed of the block.
Calculate the maximum kinetic energy of the block.
Determine the speed of the block when it is from the equilibrium position.
Explain why the potential and kinetic energy vary during the motion, even though their sum remains constant.
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.
A string of length is fixed at both ends and supports standing waves. The wave speed is .
Derive an expression for the wavelength of the harmonic on the string.
In a pipe that is closed at one end and open at the other, only certain harmonics are observed. Explain why some harmonics are missing in such a tube.
Calculate the frequency of the fourth harmonic for the string.
Sketch the standing wave pattern corresponding to the second and fourth harmonic on the string.
Compare the harmonic series for a string fixed at both ends and a pipe closed at one end. Sketch for (d): Second harmonic: 1 full wavelength → 3 nodes, 2 antinodes Fourth harmonic: 2 full wavelengths → 5 nodes, 4 antinodes