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NEETPhysicsGravitation

Assertion (A) Angular speed, linear speed and kinetic energy change with time but angular momentum remains constant for a planet orbiting the sun. Reason (R) Angular momentum is constant as no torque acts on the planet.

Options

  1. ABoth A and R are true and R is a correct explanation for A .
  2. BBoth A and R are true but R is not a correct explanation for A .
  3. CA is true, R is false.
  4. DA is false, R is true.

Correct answer

A. Both A and R are true and R is a correct explanation for A .

Step-by-step solution

As we know that, Torque is the moment of force and torque ( )= r F where, r is distance between axis of rotation and force (F) . Also, = d L d t and since, in space there is no external torque is applied so, =0 L=0= constant Hence, Assertion (A) and Reason (R) both are true and Reason (R) is the correct explanation of Assertion (A).

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