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NEET2009PhysicsRotational MotionActual

Assertion : Angular speed of a planet around the sun increases, when it is closer to the sun. Reason : Total angular momentum of the system remains constant.

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

According to law of conservation of angular momentum, when sum of external torques acting on a system is zero, then the total angular momentum of the system remains constant. =0, L=I = Constant If I increases, decreases and vice versa.

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