Question

Draw a labelled circuit diagram of a potentiometer used to compare emfs of two given cells X and Y. (Procedure and formula are NOT required.)

Answer 1

AB: Potentiometer wire.

B/E: Driver battery in the primary circuit.

K: Plug key to start/stop current flow. 

Rh: Rheostat to control the steady current through wire AB.

E, (Cell X) & E, (Cell Y): The two cells whose EMFs are being compared.

Two-way Key: Allows switching between Cell X and Cell Y.

G: Galvanometer to detect the null (zero deflection) point. 

J: Jockey to slide along wire AB to find the balancing length.