Main Page | See live article | Alphabetical index

Joule's law

Joule's law (due to James Prescott Joule) expresses the amount of heat generated by an electrical resistor, and is expressed by the relation

Q is proportional to
by current I flowing through a resistor with resistance R for a time t, and Q is the heat generated


where k is the constant of proportionality, dependent on the units used to express I, R and t. If amperes, ohms, and seconds are used, and the result expressed in joules, it is simply 1.