What is a pulley?

A pulley is defined as a mechanical device that facilitates the change of direction of a force, enabling the lifting of heavy objects with greater ease. It consists of a wheel on an axle or shaft designed to support movement and change of direction of a cable or belt.

When a force is applied to one part of the system, such as pulling down on the rope, the pulley allows that force to be redirected to lift an object vertically. This mechanical advantage is why pulleys are widely used in various applications, from construction equipment to simple flagpoles. The effectiveness of a pulley comes from its ability to distribute weight and reduce the amount of force needed to lift an object compared to lifting it directly.

The other choices do not accurately describe what a pulley is or its primary function. A type of structural support or a tool for measuring tension does not capture the essence of a pulley’s mechanical role. Similarly, describing it as a component of electronic circuits is misleading, as pulleys are purely mechanical devices.