(n) a unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second, Syn.watt second, J
(n) English physicist who established the mechanical theory of heat and discovered the first law of thermodynamics (1818-1889), Syn.James Prescott Joule
The Collaborative International Dictionary of English (GCIDE) v.0.53
n. [ From the distinguished English physicist, James Prescott Joule (1818-1889). ] (Physics.) A unit of work which is equal to 107 ergs (the unit of work in the C. G. S. system of units), and is equivalent to one watt-second, the energy expended in one second by an electric current of one ampere in a resistance of one ohm; also called the absolute joule. It is abbreviated J or j. The international joule is slightly larger, being 1.000167 times the absolute joule. The absolute joule is approximately equal to 0.737562 foot pounds, 0.239006 gram-calories (small calories), and 3.72506 x 10-7 horsepower-hours, and 0.000948451 B.t.u. HCP61 [ 1913 Webster +PJC ]
Joule's equivalent. See under Equivalent, n. [ 1913 Webster ]
(Thermodynamics) The cycle for the air engine proposed by Joule. In it air is taken by a pump from a cold chamber and compressed adiabatically until its pressure is eqal to that of the air in a hot chamber, into which it is then delivered, thereby displacing an equal amount of hot air into the engine cylinder. Here it expands adiabatically to the temperature of the cold chamber into which it is finally exhausted. This cycle, reversed, is used in refrigerating machines. [ Webster 1913 Suppl. ]
. 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 i2Rt, 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. ]
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