Question

To compare the emf of two given primary cells using potentiometer practical

Answer 1

Answer:

Potentiometer is used to compare the Emf's of two primary cells.

The circuit connections are made as shown in the circuit diagram.

Two primary cells like Leclanche cell and Danicells are connected in a DPDT switch.

The balancing lengths of the lechlanche and Daniel cells are noted by moving the pencil jockey along the wire to get null deflectionfor the same current. The rheostat is adjusted and for different value of current. The experiment is repeated for 4 or 5 sets of readings and the values are tabulated.

By using the relation E1/E2=l1/l2 the cemf's are compared.