Q11 of 28 Page 52

The net external torque on a system of particles about an axis is zero. Which of the following are compatible with it?

As we know that


When forces are acting radially then θ=0. So,


When forces are acting on axis of rotation then r=0. So,


When forces are acting parallel to axis of rotation then its component in plane r and F is 0. Hence F=0. So,


When torques are equal and opposite then net torque is zero.


Hence correct options are a, b, c, d.

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