JEE Main & Advanced Sample Paper JEE Main - Mock Test - 4

  • question_answer
    A transverse wave is represented by the equation \[y={{y}_{0}}\sin \frac{2\pi }{\lambda }(vt-x)\]. For what value of \[\lambda \] is the maximum particle velocity equal to two times the wave velocity?

    A) \[\lambda =2\pi {{y}_{0}}\]           

    B) \[\lambda =\frac{\pi {{y}_{0}}}{3}\]

    C) \[\lambda =\frac{\pi {{y}_{0}}}{2}\]     

    D) \[\lambda =\pi {{y}_{0}}\]

    Correct Answer: D

    Solution :

    \[y={{y}_{0}}\sin \frac{2\pi }{\lambda }\,(\text{v}t-x)\]
    Particle velocity\[\frac{dy}{dt}={{y}_{0}}\times \frac{2\pi }{\lambda }\text{v cos}\frac{2\pi }{\lambda }\,(\text{vt}\,\text{-}\,\text{x)}\].              
    Maximum particle velocity \[={{y}_{0}}\times \frac{2\pi \text{v}}{\lambda }\]
    Wave velocity = v    [given]
    So,  \[{{y}_{0}}\times \frac{2\pi \text{v}}{\lambda }=2\text{v}\]
    \[\lambda =\pi {{y}_{0}}\]


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