Two sources of sounds S_{1} and S_{2} produce sound waves of the same frequency 660 Hz. A listener is moving from source S_{1} towards S_{2} with a constant speed u m/s and he hears 10 beats/s. The velocity of sound is 330 m/s. Then, u equals:

  • Option 1)

    5.5 m/s

  • Option 2)

    15.0 m/s

  • Option 3)

    2.5 m/s

  • Option 4)

    10.0 m/s

 

Answers (1)

f_{1}= apparent frequency received from S_{1}=\frac{C-u}{C}  f_{0}

f_{2}= apparent frequency received from S_{2}=\frac{C+u}{C} f_{0}

beat frequency = f_{2}-f_{1}=\left [ \frac{C+u}{C}-\frac{C-u}{C} \right ] f_{0} 

=\frac{2u}{C}f_{0}=10

\frac{2u\times 660}{330}=10

      u=\frac{10}{4}=2.5 m/s


Option 1)

5.5 m/s

Option 2)

15.0 m/s

Option 3)

2.5 m/s

Option 4)

10.0 m/s

Preparation Products

Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Test Series JEE Main April 2021

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 6999/- ₹ 4999/-
Buy Now
JEE Main Rank Booster 2021

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 13999/- ₹ 9999/-
Buy Now
Test Series JEE Main April 2022

Take chapter-wise, subject-wise and Complete syllabus mock tests and get an in-depth analysis of your test..

₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions