DUMET Medical DUMET Medical Solved Paper-2003

  • question_answer
    The period of a simple pendulum measured inside a stationary lift is found to be T. If the lift starts accelerating upwards with acceleration of g/3, then the time period of the pendulum is :

    A)  \[\frac{T}{\sqrt{3}}\]             

    B)  \[\frac{T}{3}\]

    C)  \[\frac{\sqrt{3}}{2}T\]         

    D)  \[\sqrt{3T}\]

    Correct Answer: C

    Solution :

     Key Idea: Effective acceleration increases when the lift moves upwards. The time period of a simple pendulum of length \[l\] is \[T=2\,\pi \sqrt{\frac{I}{g}}\] where g is acceleration due to gravity when lift moves up \[g=g+a=g+\frac{g}{3}=\frac{4\,g}{3}\] \[\therefore \] \[\frac{T}{T}=\sqrt{\frac{g}{g}}\] \[\therefore \] \[\frac{T}{T}=\sqrt{\frac{\frac{4}{3}g}{g}}=\frac{2}{\sqrt{3}}\] \[\Rightarrow \] \[T=\frac{\sqrt{3}}{2}T\]


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