Q. If a source emitting waves a velocity $v/4\ $ and the observer moves away from the source with a velocity v/6, the apparent frequency as heard by the observer will be (v=velocity of sound)

A) $\frac{14}{15}v$
B) $\frac{14}{9}v$
C) $\frac{10}{9}v$
D) $\frac{2}{3}v$
Explanation

(c) When source and observer both are moving in the same direction and observer is ahead of source, then apparent frequency
$v^{'} = \frac{v - v_{o}}{v - v_{s}}v = \frac{v - \frac{v}{6}}{v - \frac{v}{4}} = \frac{\frac{5v}{6}}{\frac{3v}{4}}v = \frac{10}{9}v$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

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