Assertion (A): Power developed in circular motion is always zero.… - Vidyadip

MCQ

Assertion (A): Power developed in circular motion is always zero.
Reason (R): Work done in case of circular motion is zero.

A
Both A and R are true and R is the correct explanation of A.
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false.
D
A is false but R is true.

✓

Answer

(d) A is false but R is true.
Explanation: In case of the uniform circular motion, the tangential force is zero, only force is the centripetal force. Since the velocity of the body along the direction of the centripetal force is zero, so the power developed by the centripetal force is zero or in term of work done which is zero in circular motion (because displacement is zero) thus the power which is work done per unit time is also zero.
In the case of the non-uniform circular motion, the body has velocity in the direction of the tangential force. That is why, we say that this force develops power. In uniform motion $\alpha=0, \tau=0$. No work is done.

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