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JEE Main2011PhysicsRotational MotionActual

A thin horizontal circular disc is rotating about a vertical axis passing through its centre. An insect is at rest at a point near the rim of the disc. The insect now moves along a diameter of the disc to reach its other end. During the journey of the insect, the angular speed of the disc:

Options

  1. Acontinuously decreases
  2. Bcontinuously increases
  3. Cfirst increases and then decreases
  4. Dremains unchanged

Correct answer

C. first increases and then decreases

Step-by-step solution

=0 Angular momentum is conserve I ₁ ₁= I ₂ ₂ ₂= I ₁ ₁ I ₂ I ₂ first decreases and then increases first increases and then decreases.

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