Question

A couple produces:
(A) Linear motion
(B) Rotational motion
(C) Both A and B
(D) Neither A nor B

Answer 1

Hint We know that a couple is a pair of forces which are equal in magnitude which are oppositely directed and then it is displaced by the perpendicular distance or we can say that the moment. The simplest kind of couple consists of the two equal and opposite forces whose lines of action which do not coincide. This is usually called a ‘simple couple’. Based on this concept we have to answer this question.

Complete step by step answer
We know that a couple consists of two parallel forces that are equal in magnitude, which are opposite in sense and do not share a line of action. It does not produce any translation, but only rotational motion.
By rotational motion we mean that it occurs if every particle in the body moves in a circle about a single line. This line is known as the axis of rotation. Then we can say that the radius vectors from the axis to all particles undergo the same angular displacement at the same time. The axis of rotation need not go through the body.
Examples of such situations where we face rotational motions are fan moving in the house, table fan, hand blender’s blades motion.

Hence, we can say that a couple produces rotational motion. So, the correct answer is option B.

Note We know that the formula of the couple is given as the multiplication of position vector and the perpendicular distance. This is obtained using the vector analysis. Vector analysis is defined to be a branch of mathematics that deals with the quantities that have both magnitude and the direction.
Some of the physical and geometric quantities, which are called scalers, can be fully defined by specifying their magnitude in suitable respective units of measure. There are various applications of this field in the gravitational fields, electromagnetic fields, and the fluid flow.