Moment of Couple

—The product of two component forces which imparts a twist or turning movement to a body capable of rotation. Applied to an electric motor, the moment of couple or the torque is the twisting force which is exerted upon the armature by the pa age of an electric current through it. The two components of the torque are (a) the pull measured in pounds, and (b) the distance in feet from the center of the shaft to the point where the pull is applied. Since a couple has no single resultant, no single force can balance a couple. To prevent the rctation of a body acted on by a couple the application of two other forces is required, forming a second couple.