Q. For a given temperature difference which of the following pairs will generate maximum thermo-emf?

A) Lead-nickel
B) Copper-iron
C) Gold-silver
D) Antimony-bismuth
Explanation

(d) Thermocouples are widely used type of temperature sensor and are used as means to convert thermal potential difference into electric potential difference, using different combinations of metals. If metals were arranged according to their heating contrasts a series were formed antimony, iron, zinc, silver, gold, lead, mercury, copper, platinum and bismuth. The greater the heating contrasts between metals, the greater the electromotive force (EMF). Antimony and bismuth formed the best junction for emf.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.