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MHT CET202525 Apr 2025Evening ShiftPhysicsRotational MotionActual

The moment of inertia of a solid sphere of mass ' m ' and radius ' R ' about its diametric axis is 'I'. Its moment of inertia about a tangent in the plane is

Options

  1. A2 5 I
  2. B3 0 I
  3. C3 5 I
  4. D4 I

Correct answer

C. 3 5 I

Step-by-step solution

Moment of inertia about diameter : I = 2 5 mR^2 Using the parallel axis theorem, the moment of inertia about a tangent in the same plane is I_ tangent = I + mR^2 . Substituting mR^2 = 5 2 I from the first expression gives I_ tangent = I + 5 2 I = 7 2 I . The moment of inertia about the tangent is therefore 3.5 times that about the diameter, matching option C.

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