Officer Aptitude Rating (OAR) Test 2025 – 400 Free Practice Questions to Pass the Exam

In mechanical terms, a screw is defined as a shaft that has an inclined groove along its surface, which is known as a helical thread. This design allows the screw to convert rotational motion into linear motion, making it an essential fastening and driving tool in various applications. The inclined groove enables the screw to grip into materials, allowing it to be securely fastened.

This definition highlights the crucial aspect of the screw's structure, which is the spiral thread that provides both strength and the ability to lift or hold objects when turned. The other options do not accurately represent the function and design of a screw, as they refer to different mechanical components that serve distinct purposes. For instance, a shaft with a flat surface does not have the necessary helical threading, and a cylinder with a fixed end does not embody the function of a screw. Similarly, a pulley primarily serves to change the direction of force rather than providing the mechanical interlocking characteristic synonymous with screws.