The `n` rows each containinig `m` cells in series are joined parallel. Maximum current is taken from this combination across jan external resistance of `3 Omega` resistance. If the total number of cells used are 24 and internal resistance of each cell is `0.5 Omega` then

Options

A. `m = 8, n = 3`
B. `m = 6, n = 4`
C. `m = 12, n = 2`
D. `m = 2, n = 12`

Answer

C

Explanation

`n` : number of rows
`m` : total no. of cells in a row
. `R = 3 Omega, r = 0.5 Omega`
`mn = 24`…(i)
From maximum current in `R`
`R = (mr)/(n) rArr 3 = (m)/(n) xx 0.5` …(ii)
`m = 6 n`
`mn = 24 rArr 6n^2 = 24 rArr n = 2, m = 12`.