# Electrical Catechism: An Introductory Treatise on Electricity and Its Uses

McGraw-Hill Book Company, 1901 - Electrical engineering - 415 pages

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Page 55 - As a unit of resistance, the international ohm, which is based upon the ohm equal to 10" units of resistance of the CGS system of electromagnetic units, and is represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice, 14.4521 grams in mass, of a constant cross-sectional area and of the length of 106.3 centimetres.
Page 56 - As a unit of current, the international ampere, which is one-tenth of the unit of current of the CGS system of electro-magnetic units, and which is represented sufficiently well for practical use by the unvarying current, which, when passed through a solution of nitrate of silver in water in accordance with accompanying specifications,1 deposits silver at the rate of o.ooi 1 1 8 of a gramme per second.
Page 56 - As a unit of electro-motive force, the international volt, " which is the electro-motive force that, steadily applied to a " conductor whose resistance is one international ohm, will '• produce a current of one international ampere...
Page 494 - For compressible flow this becomes: where y is the ratio of the specific heat at constant pressure to that at constant volume and M is the local Mach number (see below for definition), y has a mean value of 1-4 for air.
Page 57 - As a unit of quantity, the international coulomb, which is the quantity of electricity transferred by a current of one international ampere in one second. As a unit of capacity, the international farad, which is the capacity of a condenser charged to a potential of one international volt by one international coulomb of electricity.
Page 92 - The lower limit is specified for rubber-covered wires to prevent gradual deterioration of the high insulations by the heat of the wires, but not from fear of igniting the insulation. The question of drop is not taken into consideration in the above tables.
Page 55 - ... represented by the resistance offered to an unvarying electric current by a column of mercury at the temperature of melting ice fourteen and four thousand five hundred...
Page 56 - The unit of current shall be what is known as the international ampere, which is one-tenth of the unit of current of the centimeter-gram-second system of electro-magnetic units, and Ampere is the practical equivalent of the unvarying current, which, when passed through a solution of nitrate of silver in water in accordance with standard specifications, deposits silver at the rate of one thousand one hundred and eighteen millionths of a gram per second.