Question

If external torque acting on the system along $x-$ axis add up to zero, then

• A. Angular momentum of system along $x-$ axis is always zero.
• B. Angular momentum of system along $y-$ axis remains constant.
• C. Angular momentum of system along $z-$ axis remains constant
• D. Angular momentum of system along $x-$ axis remain constant.

Answer 1

The correct option is D Angular momentum of system along $x-$ axis remain constant.

As external torque is zero along $x-$ axis is zero.
$\therefore$ Angular momentum of system along x-axis remain constant (may or may not be zero)
So, option (d) is correct.