A battery consists of a variable number `n` of identical cells having internal resistance connected in series. The terminals of the battery are short circuited and the current `I` measured. Which one of the graph below shows the correct relationship between `I` and `n`?

Options

A.
B.
C.
D.

Answer

C

Explanation

If n identical cells are connected in series, then Equivalent emf of the combination,
`E_(eq) = nE`
Equivalent internal resistance,
`I_(eq)=nr`
`therefore` Current, `I=E_(eq)/I_(eq) = (nE)/(nr)` or `I=E/r`=constant
Thus, current (I) is independent of the number of cells (n) present in the circut. therefore the graph showing the relationship between I nad n would be as shown below.