Q. The angular momentum of a wheel changes from $2L$ to $5L$ in $3\ seconds$. What is the magnitude of the torque acting on it
A) $L$
B) $L/2$
C) $L/3$
D) $L/5$
Explanation
(a) $\tau = \frac{dL}{dt} = \frac{L_{2} - L_{1}}{\mathrm{\Delta}t} = \frac{5L - 2L}{3} = \frac{3L}{3} = L$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.