Answer: ω/4.
- A ω/4
- B 4ω
- C ω/2
- D 2ω
Correct answer: A. ω/4
Explanation: L = Iω = (2/5)MR²ω. New I = (2/5)M(2R)² = 4 × (2/5)MR². For L conservation: ω' = ω/4.
Torque about axis O equals the force F multiplied by the perpendicular distance r⊥ from the axis to the line of action of the force, producing rotation.
Concept context
Moment of inertia, torque, angular momentum, rolling motion. Very high JEE weightage.
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