Question

If the PPM concentration of a gas that is being detected by the MQ2 Gas Sensor increases what will happen to its Analog Output pin?

(a) Voltage Increases

(b) Voltage Decreases

(c) Voltage becomes 0

(d) Voltage doesn’t change

This question was addressed to me during an online exam.

The query is from MQ2 Gas Sensor Module in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

Answer 1

Correct option is (a) Voltage Increases

To elaborate: The MQ2 Gas Sensor has two output pins, one is digital and one is analog. The analog pin’s voltage is set so that it is directly proportional to the PPM value in the air subject to variation in calibration from the potentiometer, so as the PPM level rises so does the voltage in the analog output pin until it reaches 5V.