Question

In a potentiometer experiment the balancing length for acell was found to be 1.20 m now a resistance of 10 ohm is connected across the terminals of this cell and the balancing length become 80 cm .The internal resistance of this cell is

Answer 1

Answer:

ANSWER

Let us Consider a cell of emf E and balancing length l1

E=kl

1

potential difference is balanced by length l

2

.

V=kl

2

Internal resistance of the cell

r=(

V

E−V

)R=(

V

E

−1)R=(

l

2

l

1

−1)R

=(

560−60

560

−1)10=(

50

56

−1)10

=

5

6

=1.2Ω.