Q.

In an experiment to find emf of a cell using potentiometer, the length of null point for a cell of emf 1.5 V is found to be 60 cm. If this cell is replaced by another cell of emf E, the length of null point increases by 40 cm. The value of E is x10V. The value of x is ______.                  [2023]


Ans.

(25)

E1E2=l1l2

1.5E2=6060+40=610=35

E2=52=x10  x=25