. An elementary manual of radiotelegraphy and radiotelephony for students and operators . s,or we may suppose that these are insulated from each other andthat Some of the components cany more and others less currentthan the average, so that the total current is not distributeduniformly over the cross-section, but is denser in some places thanin others. We can then very easily prove the following statementto be true. The resistance of a conductor for uniforvi distributionof the current over its cross-section is less than that for any non-uniform, distribution of the same current. Let the large
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . s,or we may suppose that these are insulated from each other andthat Some of the components cany more and others less currentthan the average, so that the total current is not distributeduniformly over the cross-section, but is denser in some places thanin others. We can then very easily prove the following statementto be true. The resistance of a conductor for uniforvi distributionof the current over its cross-section is less than that for any non-uniform, distribution of the same current. Let the large square in Fig. 6 be the section of the rod, andthe small squares into which it is divided be the componentelements. Let us suppose the total current to be equally dis-tributed over the cross-section as indicated by the uniformshading. Then the conductor has a certain resistance, and dissi-pates a certain energy per second per unit of current flowingthrough it. In the next place, let us suppose that current isremoved from one of the little elements and added to that in RADIO TELEGRAPHY. nnother, so that, whilst the current in oni? component element orwire becomes zero, represented by the small white square, that inthe other selected constituent, representctl by the doubly shadedsquare is doubled. This is in effect making the current non-uniformover the total section, without altering thetotal current flowing. The heat producedper second in any conductor by Jouleslaw is proportional to the square of thecurrent, so that if the current is doubled,the heat is Hence, if wecousider the energy dissipated as heat ineach element or filament of the wholenumber into which we have consideredthe conductor to be divided, we see thatwhen the current is uniformly distributedFig. 6. it is uniformly or equally dissipated as heat, and if there are, say, 1000 elementsor little component conductors, then the total heat produced is1000 times that in one element. If, however, we assume th
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
