Properties of Couples:

The properties that distinguish one couple from every other couple are called as its characteristics. A couple, whether negative or positive (clockwise or anticlockwise), has the following properties/characteristics.

1. The algebraic sum of the forces constitute a couple is zero.

2. The algebraic sum of the moments of the forces composing a couple is the same around any point in their plane.

3. The couple may be balanced only by another couple of the similar moment but of the opposite sense.

4. The net effect of a number of coplanar couples is equal to the algebraic sum of the effects of each couple.

A couple is often indicated by a clockwise or counter-clockwise arrow while coplanar force systems are involved rather than showing two separate forces.