Alberta Basic Security Training (ABST) Practice Exam 2025

Which type of device uses a beam of light to transmit information?

1. Microphone

2. Photosensor

3. Speaker

4. Camera

The correct answer is: Photosensor

The correct answer is based on the function of a photosensor. A photosensor is a device that converts light into an electrical signal. It utilizes a beam of light to detect various light levels or changes in light in its environment. This is crucial in applications where monitoring of ambient light is necessary, allowing the device to respond or transmit information accordingly. In contrast, a microphone captures sound waves and converts them into electrical signals, while a speaker generates sound from electrical signals, and a camera captures images through light but does not inherently transmit information via a beam of light as the primary function. The primary function of a photosensor is specifically designed around the interaction with light, which distinguishes it in the context of this question.