A certain electric circuit with a resistance R is supplied power simultaneously from n identical storage batteries. For what internal resistance of the storage batteries will the current in the circuit be the same when they are connected in series and in parallel ?

Options

A. `r=R`
B. `r=2R`
C. `r=R^(2)`
D. `r=R/2`

Answer

A

Explanation

`I_(s)=(nE)/(R+n r)` and `I_(p)=(n E)/(nR+r)`
Given, `I_(s)= I_(p)`
`:.(n E)/(R+n r)= (n E)/(n R + r) :.r=R`