n identical cells, each of emf `epsilon` and internal resistance r, are joined in series to form a closed circuit. One cell A is joined with reversed polarity. The potential difference across any one cell is

Options

A. `(2epsilon)/(n)`
B. `(n-1)/(n)epsilon`
C. `(n-2)/(n)epsilon`
D. `(2n)/(n-2)epsilon`

Answer

A

Explanation

`I = ((n - 2)epsilon)/(nr)`
`V_(B) - V_(A) = -ir + epsilon =epsilon - ((n -2)epsilon)/(nr)r= epsilon[1 - (n-2)/(n)] = (2 epsilon)/(n)`