Lectures on Dielectric Theory and Insulation |
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absorption current alternating stress anomalous current anomalous dielectric anomalous properties appears atom cable paper centimeters charge and discharge Compt condenser conduction current conductor continuous potential curves Décombe decrease dielec dielectric absorption dielectric behavior dielectric constant dielectric loss difference of potential displacement elec electric field electric force electric intensity electromotive force electron electrostatic electrostatic induction equation experimental final frequency fundamental Galvanometer geometric capacity Hopkinson hysteresis impregnated paper increase indicated insulation ionization Jour K₁ K₂ Kilovolts layers lecture materials Maxwell Maxwell's theory moisture normal observed Ohm's law Pellat phase difference phenomena phenomenon Phil Phys Physik plate polarization potential difference power factor principle of superposition properties of dielectrics proportional rend residual charge results of experiment Schweidler shows solid dielectrics specific inductive capacity surface of separation temperature theory of absorption theory of dielectric tion tric variation Volts Wagner Wiener Sitzungsber Zeit λι
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Page 44 - ... that the phenomena of electric absorption may be expected in the case of substances composed of parts of different kinds, even though these individual parts should be microscopically small. It by no means follows that every substance which exhibits this phenomenon is so composed, for it may indicate a new kind of electric polarization of which a homogeneous substance may be capable, and this in some cases may perhaps resemble electrochemical polarization much more than dielectric polarization.
Page 44 - It appears from this that Q is always negative, that is to say, in the opposite direction to that of the current employed in charging the system. This investigation shews that a dielectric composed of strata of different kinds may exhibit the phenomena known as electric absorption and residual discharge, although none of the substances of which it is made exhibit these phenomena when alone. An investigation of the cases in which the materials are arranged otherwise than in strata would lead to similar...
Page 52 - ... whilst 7, 8, 9, 10 have a high resistance (thousands of times as great as 1, 2, or 3) and small residual charge. IV. Electrolytic conduction may occur through the soda-lime glasses at the ordinary temperature of the air. Summary. — The experiments appear to verify the fundamental hypothesis, viz. that the effects on a dielectric of past and present electromotive forces are superposable. Ohm-s law asserts the principle of superposition in bodies in which conduction is not complicated by residual...
Page 11 - E^Eo, so that our first boundary condition is, that the tangential components of the electric intensity are the same on the two sides of the surface of separation...
Page 36 - Most physicists offering explanations of absorption have apparently considered that the observed phenomena in anomalous dielectrics are not consistent with the fundamental equations of the electrostatic field, and have built up other equations based on new special properties of the dielectric, not embraced in the older theory. We shall see that in nearly every instance these are merely general hypotheses or ingenious mathematical expressions which do no more than present other descriptions of the...
Page 30 - The charges come out of the glass in the inverse order in which they go in." In Hopkinson's own words — " It seems safe to infer that the effects on a dielectric of past and present electric forces are superposable.
Page 69 - According to this view the residual charge is due to changes of the surface resistances consequent on a displacement of the free electrons under the action of the field of force.
Page 83 - He conceived a simple model of a Maxwell dielectric consisting of two condensers in series, one having an infinite resistance and the other a definite value of conductivity. He investigated the behavior of this model under alternating potential difference and found that it accounted approximately for the results of experiment.
Page 51 - Glasgow, but never otherwise published them, proving that the charges come out of -the glass in the inverse order to that in which they go inf.