An observer is approaching a stationary source with a velocity (1/4) th of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is

Question

An observer is approaching a stationary source with a velocity (1/4) th of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is (A)  4:5  (B)  5:4  (C)  2:3  (D)  3:2

Tardigrade Admin · Accepted Answer

When an observer is moving towards the source apparent frequency n=n× ( (v1+vo/v) ) Or n=n× ( (v+v/4/v) ) Or n=n× (5/4) Or (n/n)=(5/4)

Q. An observer is approaching a stationary source with a velocity $\frac{1}{4}^{t h}$ of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is

$4 : 5$

$5 : 4$

$2 : 3$

$3 : 2$

$2 : 5$

When an observer is moving towards the source apparent frequency
$n = n \times (\frac{v _{1} + v _{o}}{v})$
Or $n = n \times (\frac{v + v /4}{v})$
Or $n = n \times \frac{5}{4}$
Or $\frac{n}{n} = \frac{5}{4}$

Q. An observer is approaching a stationary source with a velocity 41​th of the velocity of sound. Then the ratio of the apparent frequency to actual frequency of source is

4:5

5:4

2:3

3:2

2:5

When an observer is moving towards the source apparent frequency n=n×(vv1​+vo​​) Or n=n×(vv+v/4​) Or n=n×45​ Or nn​=45​