Question

What does a force couple consist of?

Answer 1

Hint: In the question, we are asked to list the components composed by a force couple. If you have a basic understanding of what a force couple is, you could very easily answer this question. Along with the answer, one could list out some examples for a force couple.

Complete answer:
In the question, we are asked to explain what a force couple is. A force couple is basically known to be two forces that are equal in magnitude and opposite in the direction in which they are acting and the line of action is also different and thereby result in the body being rotated in a particular direction. This turning effect could however be measured. The turning effect which is otherwise called the moment of couple could be measured by the product of the magnitude of either force and the perpendicular distance between the lines of action of the two forces.
A force couple is known to be a ‘pure couple’ when the forces are in equal magnitude. Some of the examples are:
(1) Steering wheel of car or any other vehicle while someone is driving.
(2) A screwdriver’s action.

Note: The expression for moment of couple is given by,
$m=F\times d$
Where F is the magnitude of the either force and d the perpendicular distance between them. From the very expression, we could say that the SI unit of the couple is Nm.