Question

multiple choice question
the doppler effect is the
change in pitch due to the relative motion of the source and the receiver of a sound
change in the intensity that results from constructive or destructive interference
slow change in position of the nodes and antinodes in a slowly moving standing wave
shift of sound waves to the red wavelengths of light energy
need help? review these concept resources.
read about the concept

Explanation:

The Doppler effect is a well - known phenomenon in physics. It occurs when there is relative motion between the source of a sound (or other wave) and the receiver. When the source and receiver are moving towards each other, the frequency (and thus pitch, since pitch is related to frequency for sound) of the sound wave appears higher. When they are moving away from each other, the frequency (pitch) appears lower.

• The second option about intensity due to interference is related to wave interference (constructive or destructive) which is a different concept from the Doppler effect.
• The third option about nodes and antinodes in a standing wave is about standing wave patterns and not the Doppler effect. Standing waves have fixed nodes and antinodes (for a non - moving medium) and the description in this option is incorrect as nodes and antinodes in a standard standing wave (without considering the Doppler effect in a complex way) do not have a “slow change” in position in the context of the Doppler effect definition.
• The fourth option is incorrect because the Doppler effect for sound is about sound waves (not a shift to light wavelengths). The red - shift in light is a similar concept in astrophysics (a Doppler - like effect for light), but the question is about the Doppler effect for sound.

Answer:

change in pitch due to the relative motion of the source and the receiver of a sound