An observer moves towards a stationary source | vedclass

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

Question

(D) When an observer moves towards a stationary source,the apparent frequency $f'$ heard by the observer is given by the Doppler effect formula:$f' =

Vedclass · Accepted Answer

$20$

Vedclass · Answer

(D) When an observer moves towards a stationary source,the apparent frequency $f'$ heard by the observer is given by the Doppler effect formula:$f' = f_0 \left( \frac{v + v_o}{v} ight)$where $f_0$ is the frequency of the source,$v_o$ is the velocity of the observer,and $v$ is the velocity of sound.Given that $v_o = \frac{v}{5}$,we substitute this into the formula:$f' = f_0 \left( \frac{v + \frac{v}{5}}{v} ight) = f_0 \left( \frac{\frac{6v}{5}}{v} ight) = \frac{6}{5} f_0 = 1.2 f_0$The percentage change in the apparent frequency is calculated as:$	ext{Percentage change} = \left( \frac{f' - f_0}{f_0} ight) 	imes 100$$= \left( \frac{1.2 f_0 - f_0}{f_0} ight) 	imes 100$$= 0.2 	imes 100 = 20 \%$

An observer moves towards a stationary source of sound with a velocity one-fifth of the velocity of sound. The percentage change in the apparent frequency is ..... $\%$

Similar Questions

$A$ bus is moving with a velocity of $5 \,m/s$ towards a wall. The driver blows the horn of frequency $165 \,Hz$. If the speed of sound in air is $335 \,m/s$, then after reflection of sound wave, the number of beats per second heard by the passengers in the bus will be

The driver of a car travelling with speed $30 \, m/s$ towards a hill sounds a horn of frequency $600 \, Hz$. If the velocity of sound in air is $330 \, m/s$,the frequency of reflected sound as heard by the driver is .... $Hz$.

An observer moves towards a stationary source of sound, with a speed of one-fifth of the speed of sound. The apparent increase in the frequency heard by the observer is (in $\%$)

$A$ train is moving towards a stationary observer. Which of the following curves best represents the frequency $f$ received by the observer as a function of time $t$?

$A$ bus is moving with a velocity of $5 \, ms^{-1}$ towards a huge wall. The driver sounds a horn of frequency $165 \, Hz$. If the speed of sound in air is $335 \, ms^{-1}$, the number of beats heard per second by the passengers in the bus will be:

Vedclass Test Series

Exam Paper Generator

Online Exam Module