Question

Sufficient heating of the heater is ensured by ________

(a) increasing the temperature

(b) making use of induction coil

(c) amplifying d.c. input

(d) amplifying a.c. input

This question was posed to me in an international level competition.

I need to ask this question from True RMS Responding Voltmeter topic in portion Electronic Instruments of Electrical Measurements

Answer 1

Right choice is (d) amplifying a.c. input

The explanation is: Maximum heating of the heater is obtained by making use of an amplified a.c. input. As a result the thermocouple generates maximum voltage level in order to cause the meter deflection.