Question

A source of sound is moving towards a stationary listener with 1/10 of the speed of sound. The ratio of apparent to real frequency is ............ .
(a) 10/9
(b) 11/10
(c) (11/10)²
(d) (9/10)²

Answer 1

Answer: 10/9

Explanation:

Answer 2

Answer:

(a) The ratio of apparent to real frequency is $\frac{10}{9}$

Explanation:

In this question

We have been given that

Speed of sound =$\frac{1}{10}$

Let the real frequency = f

Apparent frequency ⇒ f' = f$[\frac{v ± v_o}{v ± v_s}]$

                                      f' = f$[\frac{v}{v - [\frac{v}{10}]]}]$  

                                      f' = f$[\frac{v}{ [\frac{9v}{10}]]}]$  

                                       f' = f$[\frac{10}{9}]$  

                                $\frac{f'}{f}$ = $[\frac{10}{9}]$  

Hence, The ratio of apparent to real frequency is  $\frac{10}{9}$