Question

How many terminals does the MQ2 Gas Sensor have?

(a) 1

(b) 3

(c) 2

(d) 4

The question was asked during an interview.

My question is taken from MQ2 Gas Sensor Module in division Interfacing of Sensors, Actuators, and Other Modules of Arduino

Answer 1

Correct answer is (d) 4

To explain I would say: The MQ2 Gas Sensor has 4 terminals. These include the Vcc for accepting positive voltage to power the sensor, GND for ground connections to complete the circuit and activate the sensor, Dout which provides a digital output terminal and an Aout which provides the analog output terminal.