Q. Three wires of copper, iron and nickel are joined to form three junctions as shown in Fig. When the temperature of junction 1 is kept $50℃$ with the other two junctions at $0℃,$ the sensitive galvanometer gives a deflection of 14 divisions. When the temperature of junction 3 is kept $50℃,$ with the other two junctions at $0℃,$ the galvanometer gives a deflection of 11 divisions. Then the deflection given by the galvanometer, when temperature of the junction 2 is kept at $50℃,$ with the other two junctions at $0℃,$ will be
A) $3\ div$
B) $11\ div$
C) $14\ div$
D) $25\ div$
Explanation
(d) At cold junction, current flows from copper to nickel and from iron to copper, and at hot junction from nickel to iron, thus the contributions add
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.