The e.m.f. of one accumulator is e, its internal resistance is r. Find the e.m.f. `epsi` and the internal resistance
`R_(i)` of a battery of n accumulators connected (Fig. 26.10):
(a) in series,
(b) in parallel,
(c) in m series-connected groups of k accumulators, `m lt n`.
k = n/m, where the accumulators are connected in parallel.

Answer

(a) `epsi=ne, R_(i)=nr;` (b) `epsi=e ; R_(i) =r//n; (c ) epsi=me, R_(i)=mr//k, =m^2r//n`.

Explanation

(a) When the cells are connected in series, their e.m.f. and internal resistances are added.
(b) When the cells are connected in parallel, the e.m.f. remaias unchanged, but the internal conductances are added.
(c) in a mixed connection we calculate first the e.m.i. and the internal resistance of a group, and then the game parameters for the battery as a whole.