Which type of sensor is commonly used to detect the distance to an object?

• A. Gyroscope
• B. Proximity sensor
• C. Pressure switch
• D. Chemical sensor

Answer: (B)

Working with distance to an object often relies on sensing without touching the object. Proximity sensors are designed for that exact purpose: they detect how close something is by emitting energy (like infrared light, sound waves, or an electromagnetic field) and sensing the response, such as a reflected signal or a change in the field. This lets a robot know when an object is nearby and, in many cases, estimate its distance to enable obstacle avoidance or safe navigation.

Gyroscopes measure rotation, not distance. Pressure switches respond to force or pressure, not proximity. Chemical sensors detect specific substances, not how far away something is.