An elementary book on electricity and magnetism and their applications . bleThrowSwitch nj to) a B [ j i If we connect an incandescent lamp in series with a condenser (Fig. 231)to a direct-current generator, the lamp is not lighted because the circuit isopen between the two sets of plates of the condenser. DC (^\LamP But when we connect the \\ // same circuit to an alterna-tor producing alternatingcurrent, the lamp glowseven though the circuit isopen between the plates ofthe condenser. If we re-move the condenser, how-ever, and place the endsof the wire near together, thus leaving the circuit
An elementary book on electricity and magnetism and their applications . bleThrowSwitch nj to) a B [ j i If we connect an incandescent lamp in series with a condenser (Fig. 231)to a direct-current generator, the lamp is not lighted because the circuit isopen between the two sets of plates of the condenser. DC (^\LamP But when we connect the \\ // same circuit to an alterna-tor producing alternatingcurrent, the lamp glowseven though the circuit isopen between the plates ofthe condenser. If we re-move the condenser, how-ever, and place the endsof the wire near together, thus leaving the circuit open, the lamp is not lighted. We say thatthe lamp glows because there is capacity in the circuit. 234. What is the action of a condenser? Perhaps we canpicture the action of a condenser by comparing it to a box ina pipe line, as shown in figure 232. This box is divided intotwo compartments C and C by means of a rubber diaphragmD, and the two compartments are connected to a pump P. Wire \ Fig. 231.—Lamp connected in series withcondenser on d-c. or a-c. Fig. 232. Water Electricity Mechanical analogue of a condenser in circuit. This reciprocating pump displaces the fluid, first in one direc-tion, as the piston travels upward, then in the other, as ittravels downward. Thus the surging of the fluid back andforth subjects the rubber diaphragm to a mechanical stress. 338 ELECTRICITY AND MAGNETISM The pump corresponds to an alternating-current generatorA, the water to the electricity, the two compartments of thebox to the two sets of plates CC in the condenser, and thediaphragm to the dielectric D of the condenser. The alternatorgenerates an alternating electromotive force which produces anelectrical stress in the insulating material DD between the metalplates CC as these plates are charged electrically first in onedirection and then in the reverse direction. Now let us study just what happens when we apply to thecondenser an alternating voltage, such as is represente
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmagnetism, bookyear19
