What is moment of a force

The general definition of the moment of force :

Moment of force is defined as a product of force and the moment arm. Now the question arise in your mind that what is moment arm? The moment arm is the perpendicular distance between the line of action of the force and the centre of moments. 

In mechanics moment of force is turning effect produced by force, on a body, on which it acts. 

Moment of force = Force applied × Perpendicular distance from the fixed axis. This formula is applied to calculate the moment of force for balanced as well as unbalanced forces. 

Moment of a force

In the above figure the moment of force = ( P × l ) N-m

If the force is in Newton and moment of force is in meter then the unit of moment of force is Newton-meter ( N-m ).