Q. A source of sound of frequency $n$ is moving towards a stationary observer with a speed $S.$ If the speed of sound in air is $V$ and the frequency heard by the observer is $n_{1},$ the value of $n_{1}/n$ is
A) $(V + S)/V$
B) $V/(V + S)$
C) $(V - S)/V$
D) $V/(V - S)$
Explanation
(d) By using $n^{'} = n\frac{v}{v - v_{S}} \Rightarrow \frac{n^{'}}{n} = \left( \frac{V}{V - S} \right)$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.