BCECE Medical BCECE Medical Solved Papers-2011

  • question_answer
    The minimum phase difference between two simple harmonic oscillations, \[{{y}_{1}}=\frac{1}{2}\sin \omega \,t+\frac{\sqrt{3}}{2}\cos \,\omega \,t\] \[{{y}_{2}}=\sin \omega \,t+\cos \,\omega \,t\], is

    A)  \[\frac{7\pi }{12}\]

    B)  \[\frac{\pi }{12}\]

    C)  \[\frac{-\pi }{6}\]

    D)  \[\frac{\pi }{6}\]

    Correct Answer: B

    Solution :

    \[{{y}_{1}}=\frac{1}{2}\sin \,\omega \,t+\frac{\sqrt{3}}{2}\cos \,\,\omega \,t\]                 \[=\cos \frac{\pi }{3}\sin \,\omega \,t+\sin \frac{\pi }{3}\cos \,\omega \,t\] \[\therefore \] \[{{y}_{1}}=\sin \,(\omega \,t+\pi /3)\]                 \[{{y}_{2}}=\sqrt{2}\left( \frac{1}{\sqrt{2}}\sin \,\omega \,t+\frac{1}{\sqrt{2}}\cos \,\omega \,t \right)\] Similarly, \[{{y}_{2}}=\sqrt{2}\sin \,(\omega \,t+\pi /4)\] Phase difference \[=\Delta \phi =\frac{\pi }{3}-\frac{\pi }{4}=\frac{\pi }{12}\]


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