farad(redirected from Petafarad)
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farad(făr`əd) [for Michael FaradayFaraday, Michael
, 1791–1867, English scientist. The son of a blacksmith, he was apprenticed to a bookbinder at the age of 14. He had little formal education, but acquired a store of scientific knowledge through reading and by attending educational lectures including, in
..... Click the link for more information. ], unit of electrical capacitancecapacitance,
in electricity, capability of a body, system, circuit, or device for storing electric charge. Capacitance is expressed as the ratio of stored charge in coulombs to the impressed potential difference in volts.
..... Click the link for more information. , equivalent to 1 coulomb of stored charge per volt of applied potential difference.
the unit of electrical capacitance in the International System of Units and in the meter-kilogram-second-ampere (MKSA) system of units. The symbol for the farad, which was named after M. Faraday, is F. One farad is the capacitance of a capacitor in which a charge of 1 coulomb produces a potential difference of 1 volt between the plates. The unit of capacitance in the centimeter-gram-second (cgs) electrostatic system is 1 cm = (109/c2) F ≈ 1.113 × 10–12F, where c is the numerical value of the speed of light in a vacuum in cm/sec. In practice, the following fractional units are used more frequently than the farad: the microfarad (µLF), which equals 10–6F, and the picofarad (pF), which equals 10–12F.