Question

When current passes through the junction of two different metals, evolution or absorption of heat at the junction is known as
(A) Seebeck effect
(B) Peltier effect
(C) Thomson effect
(D) Joule effect

Answer 1

Hint: When current is passed through two different conductors, heat will be evolved in the junction and also absorption takes place at the other end. The metals are connected in the form of a thermocouple. This is true in the case of the Peltier effect. That is, in Peltier effect heating occurs at one end and cooling occurs at the other end.

Complete answer:
Seebeck effect- An electric current is induced when the two junctions of the thermocouple are kept at different temperatures.
Peltier effect- When current is passed through two different conductors, heat will be evolved in the junction and also absorption takes place at the other end. The metals are connected in the form of a thermocouple. This is true in case of the Peltier effect. That is, in Peltier effect heating occurs at one end and cooling occurs at the other end.
Joule effect – A conductor releases heat when electric current is passed through a conductor.
Thomson effect – An emf is generated when two sections of a conductor are at different temperatures.

So, the correct answer is “Option B”.

Note:
Here all laws are related with electric current and the heat produced when current passed through a conductor. An electric current is induced when the two junctions of the thermocouple are kept at different temperatures in case of Seeback effect. When current is passed through two different conductors, heat will be evolved in the junction and also absorption takes place at the other end is the Peltier effect. Whereas, the Joule effect is that the conductor releases heat when electric current is passed through a conductor. An emf is generated when two sections of a conductor are at different temperatures in case of Thomson effect.