Answer: false.
Explanation:
Doppler effect is caused to the relative motion of the source of light/sound with respect to the observer.
If the source is moving towards you, you will perceive the frequency to be larger (also called a blue shift), while if the wave is moving away, you will perceive the frequency to be smaller (also called a red shift).
Then the statement:
"Doppler effect is caused by sound or light wave being pushed together and spread apart due to motion."
Is false
