Q. A constant torque acting on a uniform circular wheel changes its angular momentum form $A_{0}$ to 4 $A_{0}$ in 4s. The magnitude of this torque is
A) $\frac{3A_{0}}{4}$
B) $A_{0}$
C) 4$A_{0}$
D) 12$A_{0}$
Explanation
(a) $\mathbf{c} = \frac{\mathbf{dL}}{dt} = \frac{L_{2} - L_{1}}{\mathrm{\Delta}t} = \frac{4A_{0} - A_{0}}{4} = \frac{3A_{0}}{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.