JEE Main & Advanced Physics Rotational Motion Question Bank Self Evaluation Test - System of Particles Rotational Motion

  • question_answer
    Four identical thin rods each of mass M and length\[l\], form a square frame. Moment of inertia of this frame about an axis through the centre of the square and perpendicular to its plane is :

    A) \[\frac{2}{3}M{{l}^{2}}\]

    B) \[\frac{13}{3}M{{l}^{2}}\]

    C) \[\frac{1}{3}M{{l}^{2}}\]

    D) \[\frac{4}{3}M{{l}^{2}}\]

    Correct Answer: D

    Solution :

    [d] Moment of inertia of a thin rod of length \[l\] about an axis passing through centre and perpendicular to the rod \[=\frac{1}{12}M{{l}^{2}}\] Thus moment of inertia of the frame. \[\frac{m{{l}^{2}}}{12}+\frac{m{{l}^{2}}}{4}=\frac{4m{{l}^{2}}}{12}=\frac{m{{l}^{2}}}{3}\] Total M.I. \[=4\times \frac{m{{l}^{2}}}{3}\]


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