Physics · Sound Waves

JEE Advanced 2024 — Paper 1 — Question 28

A source (S) of sound has frequency 240 Hz . When the observer ( O ) and the source move towards each other at a speed $v$ with respect to the ground (as shown in Case 1 in the figure), the observer measures the frequency of the sound to be 288 Hz . However, when the observer and the source move away from each other at the same speed v with respect to the ground (as shown in Case 2 in the figure), the observer measures the frequency of sound to be nHz .

The value of n is $\qquad$ .

Question figure

Answer: 200

Numerical answer — enter this value.

Step-by-step solution

$\quad f_{0}=240 \mathrm{~Hz}$

$\mathrm{f}_{1}=\left(\frac{\mathrm{v}+\mathrm{u}}{\mathrm{v}-\mathrm{u}}\right) \mathrm{f}_{0}$

$288=\left(\frac{v+u}{v-u}\right) 240 \Rightarrow \frac{v+u}{v-u}=\frac{6}{5}$

$v=11 u$ (i) $\mathrm{f}_{2}=\left(\frac{\mathrm{v}-\mathrm{u}}{\mathrm{v}+\mathrm{u}}\right) \mathrm{f}_{0}$

(D) $\xrightarrow{u}$

$f_{2}=\frac{5}{6} \times 240=200 H z$ .

Solution figure

Answer key and solution verified before publishing.

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Exam: JEE Advanced 2024
Paper: Paper 1
Subject: Physics
Chapter: Sound Waves
Topic: Doppler Effect of Sound

A source (S) of sound has frequency 240 Hz . When the observer ( O )… | JEE Advanced 2024 PYQ with Solution · DhiX AI