Cyclopedia of applied electricity: a general reference work on direct-current generators and motors, storage batteries, electrochemistry, welding, electric wiring, meters, electric light transmission, alternating-current machinery, telegraphy, etc, Volume 1
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acid alternating current alternating-current ammeter amount amperes arc lamps arranged battery bridge building cable called capacity cause centimeter circuit breakers closed coil condenser conductor conduit connected in series cord current passes Daniell cell deflection devices Diagram direct current direction dynamo earth Electrical Engineering electrodynamometer electromotive force electroscope equal fire fixtures flow formula fuses galvanic cell galvanometer ground hazard heat incandescent lamps inch induction installation insulation internal resistance iron joint joules knob light lines of force machine magnetic field material measured megohms metal method molding motor needle Ohm's law ohms Outlet pipe placed plug pole porcelain positive charge potential difference primary produced proportional protection result rheostat rubber rubber-covered wire rules secondary short-circuit shown in Fig shows shunt sockets solution standard switch switchboard temperature terminals tion transformer tubing unit usually voltage voltmeter volts walls watts Wheatstone's bridge wire zinc
Page 82 - Required resistance : 150 :: (.010)' : (.022)' or, Required resistance = 150 X ,n 00^, = 30.99+ ohms. (•022) For a wire 400 feet long, we have, therefore, by direct proportion, Required resistance = r-57r7, X 30.99 = 6.88+. Ans. 6.88+ ohms. If a circuit is made up of several different materials joined in series with each other, the resistance of the circuit is equal to the sum of the resistances of its several parts. In calculating the resistance of such a circuit, the resistance of each part should...
Page 117 - The common unit of heat is the calorie, which is the amount oi heat necessary to raise the temperature of 1 gram of water through 1 degree Centigrade. By careful investigations it has been found that the joule is equivalent to .24 of a calorie ; that is, one joule of electrical energy when transformed into heat is equal to .24 calorie. Electrical energy may therefore be expressed in heat units by multiplying the number of joules by .24 ; that is, U=I* XHX «X.24 whare U is the heat in calories.
Page 80 - As the area of a circle is proportional to the square of its diameter, it follows that the resistances of round conductors are inversely proportional to the squares of their diameters.
Page 114 - ... twice that of the other, and send currents of equal strengths through each. The amount of heat developed in the wire of higher resistance will be twice that developed in the wire offering the lower resistance. The unit used to express the amount of mechanical work done is known as the foot-pound. The work done in raising any mass through any height is found by multiplying the weight of the body lifted by the vertical height through which it is raised; similarly, the practical unit of electrical...
Page 286 - ... inch block must be fastened between studs or floor timbers flush with the back of lathing to hold tubing, and to support switches or fixtures. When this cannot be done, wooden base blocks, not less than %. inch in thickness, securely screwed to lathing, must be provided for switches, and also for fixtures which are not attached to gas pipes or conduit.
Page 291 - Must be placed at every point where a change Is made in the size of wire (unless the cut-out In the larger wire will protect the smaller.) (c) Must be in plain sight, or enclosed in an approved cabinet, and readily accessible.
Page 251 - 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 334 - Cables may be supported in approved junction boxes on two or more insulating supports so placed that the conductors will be deflected at an angle of not less than 90 degrees, and carried a distance of not less than twice the diameter of the cable from its vertical position. Cables so suspended may be additionally secured to these insulators by tie wires.