# Q. To draw maximum current from a combination of cells, how should the cells be grouped?

AFMCAFMC 2006

Solution:

## Current taken from the combination of n cells each of internal resistance r in series with externaI resistance R is $i = \dfrac{nE}{nr + R}$ Similarly, for paralleI combination $i = \dfrac{nE}{r + nR}$ For mixed grouping of n such cell in m rows with externaI resistance R is $i = \dfrac{mnE}{mR + nr}$ It is obvious that maximum current obtained from each combination depends on relative vaiues of external and internaI resistance.

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