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NEET2019PhysicsRotational MotionActual

Assertion : A person standing on a rotating platform suddenly stretched his arms. The platform slows down. Reason : This happens as angular momentum is conserved.

Options

  1. AIf both assertion and reason are true and reason is the correct explanation of assertion.
  2. BIf both assertion and reason are true but reason is not the correct explanation of assertion.
  3. CIf assertion is true but reason is false.
  4. DIf both assertion and reason are false.

Correct answer

A. If both assertion and reason are true and reason is the correct explanation of assertion.

Step-by-step solution

On stretching arms, his moment of inertia (I) increases. As no torque has been applied, therefore I = constant. As I increases, decreases.

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