Question

The angular momentum of a rotating body changes from `A_(0)` to `4 A_(0)` in 4 min. The torque acting on the body is
A. `(3)/(4)A_(0)`
B. `4 A_(0)`
C. `3 A_(0)`
D. `(3)/(2)A_(0)`

Answer 1

Correct Answer - A
Torque = Rate of change of angular momentum `(tau)=(dL)/(dt)`
Given, `dL=4A_(0)-A_(0)=3A_(0),dt=4 min`
`rArr` Torque acting on the body, `tau=(3)/(4)A_(0)`.