Question

A couple produces

• A. purely translational motion
• B. purely rotational motion
• C. both translational and rotational motion
• D. no motion

Hint:

A couple defined more than two forces operating on a body in equal and opposing directions with an interval between their lines of action.

Answer 1

The Correct Option is B

To determine the effect of a couple on a body, we need to understand the concept of a couple in physics.

Definition of a Couple: A couple consists of two equal and opposite forces whose lines of action do not coincide. These forces create a rotation without causing any translation.

Explanation:

• A couple produces a rotational motion because the two equal forces create a torque. The torque is a turning effect caused by a force acting at a distance from a pivot point or axis of rotation.
• Since the forces in a couple are equal in magnitude but opposite in direction and do not act along the same line, they cancel each other out in terms of linear force. Thus, they produce no net translational force on the object.
• The result of a couple is purely rotational motion without any translation, because the net force is zero, but the net torque is not zero.

Conclusion: Among the given options, the correct answer is that a couple produces "purely \ rotational \ motion". This is because a couple induces rotational motion around a point without causing any linear displacement of the center of mass.