2. Questions Bank
  3. JEE Main & Advanced
  4. Physics
  5. Wave Mechanics

JEE Main & Advanced Physics Wave Mechanics Question Bank Critical Thinking

  • question_answer
    Two whistles A and B produces notes of frequencies 660 Hz and 596 Hz respectively. There is a listener at the mid-point of the line joining them. Now the whistle B and the listener start moving with speed 30 m/s away from the whistle A. If speed of sound be 330 m/s, how many beats will be heard by the listener                                   [RPET 1996]

    A)            2    

    B)            4

    C)            6    

    D)            8

    Correct Answer: B

    Solution :

                For observer note of \[B\] will not change due to zero relative motion.                    Observed frequency of sound produced by A                    = \[660\frac{(330-30)}{330}=600\,Hz\]                    \[\therefore \] No. of beats = 600 ? 596 = 4


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