Which component is a sensor?

• A. Outdoor camera
• B. Garden light
• C. Internet
• D. 100K resistor

Answer: (A)

In IoT, a sensor is anything that detects a physical quantity and converts it into a signal the system can read. An outdoor camera fits this role because it contains an image sensor that detects light and creates digital data representing the scene, and it can also detect motion. The garden light is an actuator—it emits light in response to a control signal rather than measuring something. The Internet is a communication network, not a sensing element. A 100K resistor is a passive component used to control current or voltage, not to sense environmental changes. So the outdoor camera is the component that serves as a sensor.