Definition
The ohm is defined as a resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force.
where:
- V = volt
- A = ampere
- m = meter
- kg = kilogram
- s = second
- C = coulomb
- J = joule
- S = siemens
In many cases the resistance of a conductor in ohms is approximately constant within a certain range of voltages, temperatures, and other parameters; one speaks of linear resistors. In other cases resistance varies (e.g., thermistors).
Commonly used multiples and submultiples in electrical and electronic usage are the milliohm, kilohm, megohm, and gigaohm, though the term 'gigohm', though not official, is in common use for the latter.
In alternating current circuits, electrical impedance is also measured in ohms.
Read more about this topic: Ohm
Famous quotes containing the word definition:
“Scientific method is the way to truth, but it affords, even in
principle, no unique definition of truth. Any so-called pragmatic
definition of truth is doomed to failure equally.”
—Willard Van Orman Quine (b. 1908)
“It’s a rare parent who can see his or her child clearly and objectively. At a school board meeting I attended . . . the only definition of a gifted child on which everyone in the audience could agree was “mine.””
—Jane Adams (20th century)
“... we all know the wag’s definition of a philanthropist: a man whose charity increases directly as the square of the distance.”
—George Eliot [Mary Ann (or Marian)