A student measures the terminal potential difference `(V)` of a cell (of emf `epsilon` and internal resistance `r`) as a function of the current `(I)` flowing through it. The slope and intercept of the graph between `V` and `I`, then respectively, equal

Options

A. `E and -r`
B. `-r and E`
C. `r and -E`
D. `- E and r`

Answer

B

Explanation

`V = E - Ir`
`V v//s I` graph : `y = E - xr` (straight line)
Comparing with `y = C + mx`
Slope `m = -r`, intercept `C = E`.