Question

Two dissimilar metals joined at their ends kept at constant temperature constitute ,a thermocouple ?is it true?

Answer 1

see below

Explanation:

For having a thermocouple you must have two different metallic conductors, joined together at their ends, but also two different temperature where there are the two coupling.

That because if a conductor is put in a place with two different tempereture between the two ends you have a shift of electrons from the point with the higter temperature toward the point with the lower one. But this difference that caused a difference of tension is not the same for all the metals but depends by the particular metal that you use.

So joining toghether metals with different "force" you have a difference di tension `Delta V` gived by `Delta V_1-Delta V_2` and a conseguent electric current