Question

If torque is zero then:

• A. angular momentum is conserved
• B. linear momentum is conserved
• C. energy is conserved
• D. angular momentum is not conserved

Answer 1

Answer: (A)

angular momentum is conserved

Answer 2

Torque is the rate of change of angular momentum. That is, $\tau=\frac{d L}{d t}$
If torque $(\tau)$ is zero, then $\frac{d L}{d t}=0$
or $L =$ constant
i.e., angular momentum of the system is conserved.