JEE Main & Advanced Sample Paper JEE Main Sample Paper-46

  • question_answer
    A uniform rod of length \[l\]and mass M is suspended on two vertical inextensible string as shown in the figure. Calculate tension T in left string at the instant, when right string snaps.  

    A)  \[mg/2\]          

    B)  \[mg\]

    C)  \[mg/4\]          

    D)  \[mg/8\]

    Correct Answer: C

    Solution :

     Let the tension in the string be T and the acceleration of the centre of mass of the rod downwards be a. Then, \[mg-T=ma\] Again, \[\frac{mgl}{2}=I\,\,\alpha =\frac{m{{l}^{2}}}{3}\times \frac{a}{l/2}\] \[\Rightarrow \]            \[a=\frac{3}{4}g\] \[\therefore \]    \[T=\frac{mg}{4}\]

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