Joule’s law of the heating effect of the current state that the amount of heat produced in a resistor is,
(i) directly proportional to the square of the current (H ∝ I2)
(ii) directly proportional to the resistance of the resistor (H ∝ R)
(iii) directly proportional to the time for which the current flows through the resistor (H ∝ t)
combining all three we get,
H ∝ I2Rt
