964 



Dr. Gr. Breifc on the Effective Capacity of 



The coil is supposed to be wound in regular layers, 

 the spacing of the wires in each layer being the same 

 and the spacing of one layer from another being also 

 the same for all layers but not necessarily the same as the 

 spacing of the wires in each layer. This is shown in fig. 2, 

 where hi is the spacing of the wires in one layer, and h 2 the 

 spacing between two adjacent layers. 



Fig'- 1- — Section of coil with circular cross section. 



r 



B 





It will also be supposed in what follows that the number 

 of turns in each layer is so large that the potential drop in 

 any one of them is negligible in comparison with the whole 

 potential drop in the layer. It is further assumed that the 

 number of layers is so large that the potential drop in any 

 one layer is only a small fraction of the potential drop in 

 the whole coil. 



These assumptions are clearly realized in practice only if 

 very thin wire is employed in winding the coil. 



Under the conditions mentioned above, it is immaterial 



