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 <math>I^2 R t</math>

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

or

<math>Q = k I^2 R t</math>

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.

<math>units = J / A^2 \Omega s</math>