Question

When two wires of different material are joined together at either end, forming two junctions which are maintained at a different temperature, a _________ force is generated.

(a) thermo-motive

(b) electro-motive

(c) chemical reactive

(d) mechanical

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

My query is from Transducers for Body Temperature Measurement in division Physiological Transducers of Biomedical Instrumentation

Answer 1

Right answer is (a) thermo-motive

The explanation: When two wires of different material are joined together at either end, forming two junctions which are maintained at a different temperature, a thermo-motive force is generated causing a current to flow around the circuit. This arrangement is called thermocouple. The junction at higher temperature in thermocouple is termed as measuring junction. The junction at lower temperature in the thermocouple is called the reference temperature.