The Doppler shift involves a shift in the . Check all that apply. Group of answer choices actual intensity produced by the source of sound actual frequency produced by the source of sound the perceived pitch of sound observed by a listener the loudness of sound observed by a listener none of these

actual frequency produced by the source of sound

Explanation:

According to Oxford dictionary; Doppler effect is"an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move towards (or away from) each other."

The actual change in frequency of a wave is called the Doppler shift. The Doppler shift is caused by a constant relative motion between the source of the wave and the observer. This leads to a change in the observed frequency of the wave.