My assumption is that it is an error that has just propagated from one part of the e-book into that section when the files were created (somewhere in the e-book that diagram is used in its correct context!). I will request that it be moved.I'll second that. The description of a parallel plate capacitor in that context seems 'quaint' to say the least. Better would be some pictures to highlight the vocabulary which was just introduced. Pictures are worth many words.
by Jake Hertz
by Aaron Carman
by Robert Keim
by Aaron Carman