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MHT CET202121 Sep 2021Evening ShiftPhysicsRotational MotionActual

Three rings each of mass ' M ' and radius ' R ' are arranged as shown in the figure. The moment of inertia of system about axis YY' will be

Options

  1. A5 MR ^2
  2. B7 2 MR ^2
  3. C3 2 MR ^2
  4. D3 MR ^2

Correct answer

B. 7 2 MR ^2

Step-by-step solution

The moment of inertia of the upper ring about its diameter is given by I ₁= MR ^2 2 The moment of inertia of the two lower rings about a tangent in their plane is given by I ₂= I ₃= 3 2 MR ^2 Total moment of inertia I = I ₁+ I ₂+ I ₃ = MR ^2 2 + 3 2 MR ^2+ 3 2 MR ^2= 7 2 MR ^2

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