Physics - Sound Wave Question with Solution | TestHub

PhysicsSound WaveDopler's effectMedium2 minPYQ_2020

PhysicsMediumsingle choice

A train moves towards a stationary observer with speed $34 m s^{- 1}$ . The train sounds a whistle and its frequency registered by the observer is $f_{1}$ . If the train's speed is reduced to $17 m s^{- 1}$ , the frequency registered is $f_{2}$ . If the speed of sound is $340 m s^{- 1}$ , then the ratio $\frac{f_{1}}{f_{2}}$

Options:

Answer:

Solution:

Here, $v_{s_{1}} = 34 m s^{- 1}$ ,

$v = 340 m s^{- 1}$

$f_{1} = \frac{v \times n}{v - v_{s_{1}}} = \frac{340 \times n}{340 - 34} = \frac{340}{306} n$

$f_{2} = \frac{v \times n}{v - v_{s_{2}}} = \frac{340 \times n}{(340 - 17)} = \frac{340 n}{323}$

$\frac{f_{1}}{f_{2}} = \frac{323}{306} = \frac{19}{18}$

Stream:JEESubject:PhysicsTopic:Sound WaveSubtopic:Dopler's effect

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...