Electric Charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. There exist two types of electric charges, called positive and negative. Positively-charged substances are repelled from other positively-charged substances, but attracted to negatively-charged substances; negatively-charged substances are repelled from negative and attracted to positive. An object will be negatively charged if it has an excess of electrons, and otherwise be positively charged or uncharged. The SI unit of electric charge is the coulomb (C), although in electrical engineering it is also common to use the ampere-hour (Ah), and in chemistry it is common to use the elementary charge (e) as a unit. The symbol Q is often used to denote a charge. The study of how charged substances interact is classical electrodynamics, which is accurate insofar as quantum effects can be ignored.
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Famous quotes containing the words electric and/or charge:
“Persons grouped around a fire or candle for warmth or light are less able to pursue independent thoughts, or even tasks, than people supplied with electric light. In the same way, the social and educational patterns latent in automation are those of self- employment and artistic autonomy.”
—Marshall McLuhan (1911–1980)
“The Germans are called brutal, the Spanish cruel, the Americans superficial, and so on; but we are perfide Albion, the island of hypocrites, the people who have built up an Empire with a Bible in one hand, a pistol in the other, and financial concessions in both pockets. Is the charge true? I think it is.”
—E.M. (Edward Morgan)