Question

A constant torque acting on a uniform circular wheel changes its angular momentum from $A_o$ to ${4A}_o$ in $4$ seconds. The magnitude of this torque is:

• A. $\frac{3}{4}{A}_o$
• B. $A_o$
• C. ${4A}_o$
• D. ${12A}_o$

Answer 1

Answer: (A)

$\frac{3}{4}{A}_o$

Torque is rate of change of angular momentum=$\frac{4A_0-A_0}{4}=\frac{3A_0}{4}$