Question

Two batteries of ε1 and ε2 (ε2 > ε1) and internal resistance r1 and r2 respectively are connected in parallel as shown in figure. [NCERT Exemplar]

Answer 1

Answer:

a) The equivalent emf of the two cells is between ε1 and ε2, i.e. ε1< εeq < ε2.

(b) The equivalent emf is smaller than ε1.

(c) The equivalent emf is given by εeq = ε1 + ε2 always.

(d) εeq is independent of internal resistances r1 and r2.

Ans. (a): We know that equivalent emf in parallel combination of cells is:

Clearly, part ‘c’ and ‘d’ are discarded by formula. This formula suggests that .

So verifies answer (a).