Bennett Mechanical Comprehension Practice Test 2025 - Free Practice Questions and Review Guide

The statement that gears help increase speed but not direction is incorrect because gears can be designed to change both speed and direction of motion. When two gears mesh, they can either increase or decrease the speed of the output gear compared to the input gear, and they can also change the direction of rotation. For instance, if one gear is turning clockwise, the gear it is meshed with will turn counter-clockwise. This ability to manage both speed and direction is a fundamental characteristic of gear systems.

The other statements are accurate. Gears can indeed produce mechanical advantage, which means they can help in lifting or moving heavy loads with less effort. Additionally, while gears are typically not designed specifically to increase friction, they can create friction between their teeth that assists in transmitting torque without slipping. Lastly, gears are machines that effectively change both speed and direction, making them versatile components in various mechanical systems.