Answer:
True
Step-by-step explanation:
Doppler's effect is the apparent change in the wavelength and frequency of a wave as it moves towards or away from an observer.
- The relative motion between the observer and the source causes changes to the wavelength and frequency.
- This effect is the doppler's effect.
- When a source moves closer, the frequency of the wave increases.
- For example, we see that effect of water ripples when a stone is dropped in still water.