# 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

or

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.