Doppler effect true statement?

Doppler effect true statement?

• A. It only occurs with moving sources, not observers
• B. It occurs only in air
• C. It occurs due to relative motion between source and observer
• D. It is a reflection phenomenon

Answer: (C)

The Doppler effect is about how the frequency we observe from a wave changes when the source and the observer move relative to each other. The waves travel at a constant speed in a given medium, so if the source moves toward the observer, the wave crests arrive more frequently, making the observed pitch higher. If the source moves away, the crests arrive less often, making the pitch lower. The key idea is that what changes is the relative motion between the two, not just the motion of the source alone. This effect can occur when the observer moves or when the source moves, and in the case of light it also shows up in vacuum due to relativistic effects. It’s not about bouncing or reflecting waves, and it’s not limited to air. The statement that best captures the phenomenon is that it occurs due to the relative motion between the source and the observer.

The Doppler effect is about how the frequency we observe from a wave changes when the source and the observer move relative to each other. The waves travel at a constant speed in a given medium, so if the source moves toward the observer, the wave crests arrive more frequently, making the observed pitch higher. If the source moves away, the crests arrive less often, making the pitch lower. The key idea is that what changes is the relative motion between the two, not just the motion of the source alone.

This effect can occur when the observer moves or when the source moves, and in the case of light it also shows up in vacuum due to relativistic effects. It’s not about bouncing or reflecting waves, and it’s not limited to air. The statement that best captures the phenomenon is that it occurs due to the relative motion between the source and the observer.