BCECE Medical BCECE Medical Solved Papers-2009

  • question_answer
    Which of the following functions does not represent a stationary wave? Here a, b and c are constants.

    A)  \[y=a\cos bx\sin ct\]

    B)  \[y=a\sin bx\cos ct\]

    C)  \[y=a\sin \,(bx+ct)\]

    D)  \[y=a\sin \,(bx+ct)+a\sin \,(bx-ct)\]

    Correct Answer: C

    Solution :

    Two superimposing waves are incident wave \[{{y}_{1}}=a\,\sin \,(\omega \,t-kx)\] and reflected wave\[{{y}_{2}}=a\,\sin \,(\omega \,t+kx)\] Then by principle of superposition                 \[y={{y}_{1}}+{{y}_{2}}\]                 \[=a[\sin \,(\omega \,t-kx)+\sin \omega \,t+kx)]\] \[\Rightarrow \] \[y=2a\,\cos \,kx\,\sin \,\omega \,t\] Therefore, option  doesnot represent a stationary wave.


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