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MHT CET202020 Oct 2020Morning ShiftPhysicsRotational MotionActual

Two circular rings 'A' and 'B' of radii 'nR' and 'R' are made from the same wire. The moment of inertia of 'A' about an axis passing through the centre and perpendicular to the plane of 'A' is 64 times that of the ring 'B'. The value of ' n ' is

Options

  1. A8
  2. B3
  3. C6
  4. D4

Correct answer

D. 4

Step-by-step solution

I _ A I _ B = 64 1 64= m_ A r_ A ² m_ B r_ B ² = 2 r_ A 2 r_ B r_ A ² r_ B ² = r_ A ³ r_ B ³ =n³ n=4

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