On the Production of Heat by Voltaic Electricity

In 1840, English physicist James Prescott Joule published his work "On the Production of Heat by Voltaic Electricity." This paper described what is now known as Joule's law, stating that the heat produced in a wire by an electric current is proportional to the product of the wire's resistance and the square of the current. This principle, known as Joule heating, explains the conversion of electrical energy into heat energy due to resistance in an electrical circuit. Joule's research was foundational to the law of conservation of energy, establishing that mechanical, electrical, and heat energies are fundamentally the same and can be interconverted. The unit of energy, the joule, is named in his honor.123