A cell having an emf E and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by

Options

A.
B.
C.
D.

Answer

C

Explanation

`V =IR = (E/(R + r))R rArr V= E/(1 + r/R)`
When `R to infty`, then, `V to E`