JEE MainPhysicsRotational MotionMCQ+4 / −1
A circular disk of radius R meter and mass M kg is rotating around the axis perpendicular to the disk. An external torque is applied to the disk such that , where is the angular position of the rotating disc as a function of time . How much power is delivered by the applied torque, when ?
- A
- B
- C
- D
View written solutionFree
Correct answer: A
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Given angular position
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Find angular velocity and angular acceleration
Angular velocity:
Angular acceleration:
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Evaluate at
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Moment of inertia of the disk
For a solid circular disk about an axis perpendicular to its plane through the center,
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Torque applied
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Power delivered by torque
Instantaneous power in rotational motion is
Therefore at s,
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Match with options
So the correct option is A.
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