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

JEE Main & Advanced Physics Wave Mechanics Question Bank Doppler's Effect

  • question_answer
    At what speed should a source of sound move so that stationary observer finds the apparent frequency equal to half of the original frequency                                           [RPMT 1996]

    A)            \[\frac{v}{2}\]                      

    B)            2v

    C)            \[\frac{v}{4}\]                      

    D)            v

    Correct Answer: D

    Solution :

               Frequency is decreasing (becomes half), it means source is going away from the observes. In this case frequency observed by the observer is            \[{n}'=n\left( \frac{v}{v+{{v}_{s}}} \right)\] Þ \[\frac{n}{2}=n\,\left( \frac{v}{v+{{v}_{S}}} \right)\] Þ\[{{v}_{S}}=v\]


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