According to the principle of moments, if the algebraic sum of moments of all the forces, acting on the body, about the axis of rotation is zero, the body is in equilibrium. Therefore, as per the principle of moments,
sum of anticlockwise moments = sum of clockwise moments
For example, a physical balance works on the principle of moments.
(i) Which force has the least moment about O? Give reason. (ii) Which force has the greatest moment about O? Give reason. (iii) Name the forces producing (a) clockwise, (b) anticlockwise moments. (iv) What is the resultant torque about the point O?