First slide

Doppler's effect

Question

A police car horn emits a sound at a frequency 240 Hz when the car is at rest. If the speed of the sound is 330 m/s, the frequency heard by an observer who is approaching the car at a speed of 11 m/s, is :

Moderate

A

248 Hz
B

244 Hz
C

240 Hz
D

230 Hz

Solution

Frequency heard by the observer
$n^{'} = n (\frac{v + v_{0}}{v}) = 240 (\frac{330 + 11}{330}) = 248 Hz .$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App