question_answer

An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency?   AIEEE  Solved  Paper-2005

A) Zero  

B)                        0.5%     

C)        5%                         

D)        20%

Correct Answer: D

Solution :

Given, \[{{v}_{o}}=\frac{v}{5}\] When observer moves towards the stationary source, then     Hence, percentage increase \[=\left( \frac{64}{320}\times 100 \right)%=20%\]