What is a gear train primarily used for?

A gear train is primarily utilized to manipulate the rotational speed and torque of a machine or mechanical system. By interconnecting several gears, which vary in size, a gear train can effectively change the rotational speed of the output gear compared to its input gear. For instance, using a larger gear to drive a smaller gear will increase the rotational speed but decrease the torque applied at the output, and vice versa, if a smaller gear drives a larger one. This versatility makes gear trains essential in many machinery and vehicles where speed adjustment and torque optimization are critical for effective performance and functionality.

The other choices refer to functions that are outside the typical applications of a gear train. Powering electrical circuits pertains to electrical engineering rather than mechanical systems. Enhancing computer processing relates to computing hardware and software, which don't involve mechanical gear systems. Lastly, measuring distance and angles is relevant to measurement tools and devices, like calipers or digital sensors, and not to gear trains.