A cell of emf `epsilon` and internal resistance r is connected across a variable load resistance R. The graph drawn between its terminal voltage and resistance R is

Options

A.
B.
C.
D.

Answer

A

Explanation

According to the question, circuit diagram of a cell is given below,

As, `Ir = E - V rArr (V)/(R ) r = E - V`
`rArr V[1+(r )/(R )] = E rArr V = (E)/(R + r).R`
General equation of a straight line passing through the origin,
y = mx
Here, y = V, `m = (E)/(R + r)` = slope of the line and x = R
As this line is passing through the origin and has a slope which reduces as R increases. Hence, the graph is