What is This Electrical Engineering MCQ Series MCQ#2:
Correct answer: 2. Humistor
Explanation & Working
A Humistor or humidity detector is a type of variable resistor whose resistance changes/varies based on humidity.
Humistors are of capacitive and impedance as well as resistive type.
A resistive humidity sensor detects resistance changes of an element. It detects relative humidity by measuring the change in the resistance of an element corresponding to the ambient humidity.
On the other hand, a capacitive humidity sensor detects humidity based on detecting change of capacitance between two detection electrodes. These electrodes are provided on a semiconductor substrate.
An impedance humidity sensor changes its electrical impedance based on the humidity change around it. This impedance is sampled to gather humidity data.
Practically humistors are employed in air conditioners so as to adjust humidity.