Which sensors are used to detect changes in light level and color?

• A. Chemical sensors
• B. Photocells and Cameras
• C. Acoustical sensors
• D. Thermal sensors

Answer: (B)

Light sensing involves two aspects: how bright something is and what color it has. A photocell responds directly to light level, changing its output as illumination changes. A camera sensor, on the other hand, not only measures brightness across the scene but also uses color filters to determine color information (red, green, blue). By combining a light-level sensor with a color-capable camera, you cover both detecting how bright the environment is and what colors appear in the view. The other sensor types don’t measure light intensity or color, so they don’t fit this requirement.