Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AIIMS2009PhysicsRotational Motion

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.

Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

A solid sphere A of radius R and mass M is attached at a point to a smaller solid sphere B of radius r 2026The angular speed of a flywheel is increased from 600 rpm to 1200 rpm in 10 s. The number of revolutions completed by the flywheel during this time is : 2026A thin wire of length ' L ' and linear mass density ' m ' is bent into a circular ring (in x - y plane) with centre ' C ' as shown in figure. The moment of inertia of the ring abou 2026A thin horizontal disc is rotating about a vertical axis passing through its fixed centre O . Its angular momentum is L_A and L_B computed about points A and B , respectively, with 2026The Sun rotates around its centre once in 27 days. What will be the period of revolution if the Sun were to expand to twice its present radius without any external influence? Assum 2025A sphere of radius R is cut from a larger solid sphere of radius 2 R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of th 2025The radius of gyration of a solid sphere of mass 5 kg about X Y is 5 m as shown in figure. The radius of the sphere is 5 x 7 ~m , then the value of x is: 2024A wheel of a bullock cart is rolling on a level road as shown in the figure below. If its linear speed is v in the direction shown, which one of the following options is correct ( 2024 Full Rotational Motion list All AIIMS PYQs