An observer moves towards a stationary source | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) When an observer moves towards a stationary source of sound,the apparent frequency heard by the observer increases.The general formula for the Dop

Vedclass · Accepted Answer

$1.2 f, \lambda$

Vedclass · Answer

(A) When an observer moves towards a stationary source of sound,the apparent frequency heard by the observer increases.The general formula for the Doppler effect is $f^{\prime} = f \left( \frac{v + v_0}{v - v_s} \right)$.Since the source is stationary,$v_s = 0$.Given that the observer's speed $v_0 = \frac{v}{5}$,the apparent frequency $f^{\prime}$ is:$f^{\prime} = f \left( \frac{v + \frac{v}{5}}{v} \right) = f \left( \frac{1.2v}{v} \right) = 1.2 f$.The wavelength of the sound waves depends only on the source and the medium. Since the source is stationary and the medium is unchanged,the wavelength reaching the observer remains $\lambda$.Therefore,the apparent frequency is $1.2 f$ and the wavelength is $\lambda$.

An observer moves towards a stationary source of sound with a speed $\frac{1}{5}^{\text{th}}$ of the speed of sound. The wavelength and frequency of the waves emitted by the source are $\lambda$ and $f$ respectively. The apparent frequency and wavelength heard by the observer are respectively,

Similar Questions

$A$ driver in a car,approaching a vertical wall,notices that the frequency of his car horn has changed from $440 \, Hz$ to $480 \, Hz$ when it gets reflected from the wall. If the speed of sound in air is $345 \, m/s,$ then the speed of the car is $....... \, km/hr$.

Two sirens situated one kilometer apart are producing sound of frequency $330 \ Hz$. An observer starts moving from one siren to the other with a speed of $2 \ m/s$. If the speed of sound is $330 \ m/s$,what will be the beat frequency heard by the observer?

Vedclass Test Series

Exam Paper Generator

Online Exam Module