Joule's laws (electrical heating)

Joule's laws describe the heat produced when electric current flows through a conductor. For constant resistance, the heat is proportional to the square of current, resistance, and elapsed time.

Connect

Joule heating: The conversion of electrical energy into thermal energy as current flows through a material. The laws quantify this heating in terms of current, resistance, and time.
Ampere: The SI base unit of electric current. Current measured in amperes is squared in the standard heating formula.
Incandescent light bulb: An electric lamp that produces light by heating a filament until it glows. Its filament's high-temperature operation is a visible result of resistive heating.
James Prescott Joule: A British physicist who investigated the relation between heat, work, and electrical current. His experiments established the quantitative connection behind electrical heating.
Peltier effect: Heating or cooling at a junction when electric current passes between two materials. Unlike Joule heating throughout a resistance, it reverses with current direction.
Electrical resistance: A measure of how strongly a material opposes electric current. At fixed current and duration, greater resistance produces more heat.
Ohm: The SI derived unit of electrical resistance. Resistance in ohms sets the heating rate at a given current.
Electric heater: A device that converts electrical energy into heat, commonly through a resistive element. Its heat output can be estimated from current, resistance, and operating time.
Joule's paddle-wheel experiment: An experiment measuring the temperature rise of water stirred by falling weights. It helped establish the equivalence of mechanical work and heat underlying Joule's account.
Seebeck effect: The production of an electric voltage from a temperature difference between materials. It converts thermal differences into voltage rather than describing current-driven resistive heat.