Question

Derive an expression for equivalent internal resistance and and emf of two cells in parallel

Answer 1

Explanation:

Let ε

1

and ε

2

be the emfs of the two cells connected in parallel.

Let r

1

and r

2

be their intermal resistance respectively

I

1

and I

2

are the currents leaving the positive electrodes of the cells.

At B

1

, currents I

1

and I

2

flow in whereas the current I flows out. Therefore I=I

1

+I

2

Let V

1

and V

2

be the potentials at B

1

and B

2

respectively.

P.d across the first cell is V

1

−V

2

=V=ε

1

−I

1

r

1