Which of the following scenarios best describes the action of a photoelectric sensor?

A photoelectric sensor operates by detecting the presence or absence of light within its environment. The scenario that best describes this action is controlling street lights based on surrounding light. In this case, the sensor can detect the level of ambient light; when the light decreases at dusk, the sensor activates the street lights to illuminate the area, and when light levels rise at dawn, it turns them off.

This functionality relies on the sensor’s ability to discern variations in light intensity, making it integral to automated lighting systems that enhance energy efficiency and public safety by only operating lights when necessary. Other scenarios involve different types of sensors and do not primarily focus on light detection. For instance, detecting motion in a room is typically handled by motion sensors that may use infrared or ultrasonic technology.