Two circular rings have masses in the ratio 1:2 and diameters 2:1. The ratio of their moment of inertia is
Correct answer: C. 2:1
- A. 1:4
- B. 4:1
- C. 2:1
- D. √2:1
Explanation
The moment of inertia of a ring is given by I=1/2 mr^2, where m is the mass and r is the radius of the ring. The mass of the rings is in the ratio 1:2, and the diameter is in the ratio 2:1, so the radius would be in the ratio 1:1/2 (since radius is half the diameter). Therefore, the moment of inertia is directly proportional to the mass and the square of the radius.
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