In this topic, you study theory, diagram & derivation of the cells in a parallel combination.
The system in which the positive of each cell are connected at one terminal and negative on the other terminal, is known as parallel combi-nation as shown in Fig. 9.19. This system is used when more current is required.
It has the following characteristics:
(i) The voltage of the combination is the same as that of the voltage per cell.
(ii) The equivalent internal resistance being connected in parallel will be
(iii) The total current is equal to the sum of the current delivered by each cell.
I = Net e. m.f. of the combination / Total (internal and external) resistance
Example. Twenty cells, each Of 1.5 V e.m.fand 0.3 Ohm internal resistance are connected in parallel. Find the current through an external resistance Of 2 Ohm.
Solution. The e.m.f. cell
1.5 v
The total internal resistance —
The total resistance R
Now current
0.744 A. Ans.
