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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीConsider the following statements regarding rotational motion about a fixed axis: (A) Only those components of external torques that lie along the axis of rotation can cause the body to rotate about the axis. (B) Torques perpendicular to the fixed axis are balanced by the constraint forces exerted by the hinges/supports. (C) Forces parallel to the axis of rotation produce non-zero torque about that axis. (D) The rate of work done by an external torque \( \tau \) rotating a body with angular speed \( \omega \) is given by \( P = \tau \omega \). How many of the above statements are correct?
Correct answer · Option 3
Only three
Explanation
Forces parallel to the axis produce zero torque about that axis because the lever arm cross product has no component along the axis, making (C) incorrect. Statements (A), (B), and (D) are correct. Thus, exactly three statements are correct.
