Question

A constant torque acting on a uniform circular wheel changes its angular momentum from $L$ to $4L$ in $4$ seconds. The torque acting on it is:

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

Answer 1

The correct option is C $\frac{3}{4}L$

As we know that, $\tau =\frac{\Delta L}{\Delta t}$

So, $\tau =\frac{4L-L}{4}=\frac{3L}{4}$