Question

What force is generated when two wires of different material are joined together at either end, forming two junctions which are maintained at a different temperature?

(a) chemical reactive

(b) electro-motive

(c) thermo-motive

(d) mechanical

I had been asked this question in final exam.

My query is from Essential Parameters for Telemedicine in division Telemedicine Technology of Biomedical Instrumentation

Answer 1

Right option is (c) thermo-motive

Easy explanation: When two wires of different material are joined together at either ends, 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 a thermocouple. The junction at a lower temperature in the thermocouple is called the reference temperature. The junction at a higher temperature in thermocouple is termed as measuring junction.