from
The Collaborative International Dictionary of English v.0.48
Joule's law \Joule's law\
1. (Elec.) The law that the rate at which heat is produced in
any part of an electric circuit is measured by the product
of the square of the current times the resistance of that
part of the circuit. If the current (i) is constant for an
interval of time (t), the energy (H) in heat units equals
i^{2}Rt, R being resistance.
[Webster 1913 Suppl.]
2. (Thermodynamics) The law that there is no change of
temperature when a gas expands without doing external work
and without receiving or rejecting heat.
[Webster 1913 Suppl.]