• Subject:


  • Topic:


A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15ms-1. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is

(Take, velocity of sound in air=330 ms-1)

(a) 800 Hz

(b) 838 Hz

(c) 885 HZ

(d) 765 Hz