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 2005]

A)  Zero                

B)  0.5%

C)  5%      

D)       20%

Correct Answer: D

Solution :

[d] Given,

When observer moves towards the stationary source, then

Hence, percentage increase