What name is given to the apparent change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source?

💡 Solution & Explanation

The Doppler effect explains the observed shift in frequency or wavelength of a wave when the source and observer are in relative motion towards or away from each other. Phenomena like the Zeeman effect involve spectral line splitting in magnetic fields, whereas the Raman effect describes inelastic scattering of photons.