Solution:
Terminal voltage Hence, the graph between V and I will be a straight line having negative slope and positive intercept.
Thermal power generated in the external circuit, Hence, graph between P and I will be a parabola passing through origin.
Also at an instant, thermal power generated in the cell = I2r and total electrical power generated in the cell
= Ei. Hence the fraction so means graph between and I will be a straight line passing through origin.