The thermocouple circuit which is used to measure temperature works on ____.

The thermocouple circuit which is used to measure temperature works on ____.

a. Seebeck effect
b. Peltier effect
c. Thomson effect
d. none of the above

Correct Answer : a. Seebeck effect

Explanation :

The Seebeck effect states that when two ends of a thermocouple are kept at different temperatures then the emf is generated in the circuit depending on the temperature difference between the hot and the cold junction. Therefore emf is a thermometric property of the circuit. The thermocouple is calibrated by measuring the thermal emf at various known temperatures, the reference junction being kept at 0° C. Peltier effect is exact opposite of Seebeck effect that the temperature difference is created by applying the voltage between two junctions of thermocouple circuit.