The Doppler effect is the change in the wavelength of light caused by the source
A) being in a high gravitational field.
B) being embedded in a cloud of dust and gas.
C) being in an intense magnetic field.
D) moving with respect to the observer.

Question

Quizplus · Accepted Answer

The Doppler effect refers to the change in frequency (or wavelength) of a wave in relation to an observer who is moving relative to the wave source. This effect is observed for all types of waves, including light. When the source of light is moving towards the observer, the wavelengths appear shorter (blue-shifted); when it is moving away, the wavelengths appear longer (red-shifted).

The Doppler Effect Is the Change in the Wavelength of Light