2. Solved Papers
  3. RAJASTHAN ­ PET

RAJASTHAN ­ PET Rajasthan PET Solved Paper-2004

  • question_answer
    Two siren 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 be 330 m/s, what will be the beat frequency heard by the observer?

    A)  8               

    B)  4

    C)  6               

    D)  1 

    Correct Answer: B

    Solution :

     \[n'=n\left( \frac{v-{{v}_{0}}}{v} \right)\] \[n''=n\left( \frac{v+{{v}_{0}}}{v} \right)\] \[\Delta n=n''-n'=\frac{2n{{v}_{0}}}{v}\] \[=\frac{2\times 330\times 2}{330}\] \[=4\]


You need to login to perform this action.
You will be redirected in 3 sec spinner