A ring and a disc have same mass and same radius. The ratio of moment of inertia of a ring about a tangent…

A ring and a disc have same mass and same radius. The ratio of moment of inertia of a ring about a tangent in its plane to that of the disc about its diameter is
  1. $6: 1$
  2. $4: 1$
  3. $2: 1$
  4. $8: 1$

Solution

Moment of inertia of a ring about a tangent in its plane is given by $I=\frac{3}{2} M R^{2}$ Moment of inertia of a disc about its diameter is given by $I^{\prime}=\frac{1}{4} M R^{2}$ $\therefore \frac{I}{I^{\prime}}=6$

Asked in: MHT CET 2020 (13 Oct Shift 1)

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