Question

Which of the following plots may represent the thermal energy produced in a resistor in a given time as a function of the electric current?

Answer 1

Plot (a) is the correct option.

When current passes through a resistor, the heat produced,
H = I²Rt,
where I = current
R = resistance of the resistor
t = time for which current is flowing
This relation shows that the heat produced for a given time in a resistor varies with the square of current flowing through it. Hence, the plot between H vs I should be a parabola symmetric along the H axis, which is represented by curve a.