According to Joule’s Law of Heating, the heat produced in an electrical circuit depends on measurable quantities—current (I), resistance (R), and time (t). The law states that the heat generated (H) in a conductor is directly proportional to the square of current, resistance of the conductor, and time for which current passes, represented by H = I²Rt. This explains why thicker wires produce less heat and why excessive current can cause heating or damage in electrical appliances.