The moment of a couple is the product of the force (i.e. one of the forces of the two equal and opposite parallel forces) and the arm of the couple.
Mathematically: Moment of a couple = F.d N-m or N-mm
- The moment of couple may be clockwise or anticlockwise.
- The effect of the couple is unchanged if::
1. The couple is shifted to any other position.
2. The couple is rotated by an angle.
3. Any pair of force whose rotation effect is the same replaces the couple.
4. Sum of forces forming couple in any direction is zero.
