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Joule's first law (also just Joule's law), also known in countries of the former USSR as the Joule–Lenz law, [1] states that the power of heating generated by an electrical conductor equals the product of its resistance and the square of the current. Joule heating affects the whole electric conductor, unlike the Peltier effect which transfers ...
Thermoelectric coolers are trivially reversible, in that they can be used as heaters by simply reversing the current. Unlike ordinary resistive electrical heating (Joule heating) that varies with the square of current, the thermoelectric heating effect is linear in current (at least for small currents) but requires a cold sink to replenish with ...
Electric heat can be accurately applied at the precise point needed in a process, at high concentration of power per unit area or volume. Electric heating devices can be built in any required size and can be located anywhere within a plant. Electric heating processes are generally clean, quiet, and do not emit much byproduct heat to the ...
The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ). [4]: 15 Electric current is also known as amperage and is measured using a device called an ammeter. [2]: 788 Electric currents create magnetic fields, which are used in motors, generators, inductors, and transformers.
The flow of charge carriers between the hot and cold regions in turn creates a voltage difference. In 1834, Jean Charles Athanase Peltier discovered the reverse effect, that running an electric current through the junction of two dissimilar conductors could, depending on the direction of the current, cause it to act as a heater or cooler. [7]
Between 1840 and 1843, Joule carefully studied the heat produced by an electric current. From this study, he developed Joule's laws of heating, the first of which is commonly referred to as the Joule effect. Joule's first law expresses the relationship between heat generated in a conductor and current flow, resistance, and time. [1]
These phenomena are known more specifically as the Seebeck effect (creating a voltage from temperature difference), Peltier effect (driving heat flow with an electric current), and Thomson effect (reversible heating or cooling within a conductor when there is both an electric current and a temperature gradient). While all materials have a ...
A heating element is a device used for conversion of electric energy into heat, consisting of a heating resistor and accessories. [1] Heat is generated by the passage of electric current through a resistor through a process known as Joule heating. Heating elements are used in household appliances, industrial equipment, and scientific ...