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?

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When current passes through a resistor, the heat produced by Joule’s heating effect is given by-

where,

I =current

R = resistance of the resistor

t = time for which current is flowing

The graph shows the variation of the heat generated by the resistor with respect to the current.

Form the above equation, we get

Which is same as the equation of parabola.

Since, heat produced for a given time in a resistor varies with the square of current flowing through it.

Thus, the curve a is the correct option.