Q.
Two similar thermocouples, made of dissimilar metals $A\ and\ B$ are connected as shown in figure through a key $K$ and a sensitive galvanometer$\ G$. One of the thermocouples is dipped in a hot bath maintained at temperature $t_{2}$ and the other in a cold bath at temperature $t_{1}$. When the key is pressed, a deflection is seen in the galvanometer because
A) An emf of the order of a few microvolt is generated which is proportional to $(t_{2} - t_{1})$
B) An emf is generated the value of which will depend upon the temperature of the hot bath only
C) An emf of about one volt is generated which will be proportional to $\left( t_{2} - t_{1} \right)$
D) An emf of a few microvolt is generated which will be proportional to $t_{2}$ only.
Explanation
(a) An emf of the order of a few microvolt is generated which is proportional to ($t_{2} - t_{1})$.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.