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NTA Abhyas JEE Main2020PhysicsRotational MotionPractice

The moment of inertia of a rigid body in terms of its angular momentum L and kinetic energy K is

Options

  1. AL 2 K
  2. BL 2 2 K
  3. CL 2 K 2
  4. DL 2 K

Correct answer

B. L 2 2 K

Step-by-step solution

Angular momentum of a rigid body about a fixed axis is given by L = I ω Where I is moment of inertia and ω is angular velocity about that axis. Kinetic energy of body is given by K = 1 2 I ω 2 ∴ K = 1 2 I I ω 2 = L 2 2 I ⇒ I = L 2 2 K

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