What is the term for the apparent change in the pitch of a sound, such as a siren, as its source moves toward or away from a listener?

Explanation

The Doppler effect describes the apparent change in frequency, or pitch, of a wave as the source and observer move relative to each other, which is why an ambulance siren sounds higher-pitched as it approaches and lower-pitched as it moves away. This same principle applies to light waves and is used in astronomy to determine whether distant stars and galaxies are moving toward or away from Earth. Radar speed guns used by traffic police also apply the Doppler effect to measure vehicle speed. Explore more Everyday Science MCQs on mcqstutor to keep practicing.