Q6.14: NCERT Physics - Part 1 SYSTEMS OF PARTICLES AND ROTATIONAL MOTION 6.14 Solution: To maintain a rotor at a uniform angular speed of 200 rad s__,…

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Q6.14: NCERT Physics - Part 1 SYSTEMS OF PARTICLES AND ROTATIONAL MOTION 6.14 Solution: To maintain a rotor at a uniform angular speed of 200 rad s__,…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often think a body rotating at constant angular speed requires no power because the net torque is zero; they forget that a non‑zero applied torque is needed to overcome friction, so power = τ ω must be computed with the actual torque, not set to zero.

To maintain a rotor at a uniform angular speed of 200 rad s__, an engine needs to transmit a torque of 180 N m. What is the power required by the engine? (Note: uniform angular velocity in the absence of friction implies zero torque. In practice, applied torque is needed to counter frictional torque). Assume that the engine is 100% efficient.