CAPACITORS

Chapter 13 CAPACITORS

Lessons In Electric Circuits Volume I – DC Book
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Summary of Contents

Lessons In Electric Circuits Volume I – DC Book

  • Chapter 13CAPACITORSContents 449,13.1 449,Electric 449,fields 449,and 449,capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . 439 454,13.2 454,Capacitors 454,and 454,calculus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 459,13.3 459,Factors 459,affecting 459,capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 462,13.4 462,Series 462,and 462,parallel 462,capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . 452 463,13.5 463,Practical 463,considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 469,13.6 469,Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45913.1Electric fields and capacitanceWhenever an electric voltage exists between two separated conductors, an electric field ispresent within the space between those conductors. In basic electronics, we study the interac-tions of voltage, current, and resistance as they pertain to circuits, which are conductive pathsthrough which electrons may travel. When we talk about fields, however, we’re dealing withinteractions that can be spread across empty space.Admittedly, the concept of a ”field” is somewhat abstract. At least with electric current itisn’t too difficult to envision tiny particles called electrons moving their way between the nucleiof atoms within a conductor, but a ”field” doesn’t even have mass, and need not exist withinmatter at all.Despite its abstract nature, almost every one of us has direct experience with fields, atleast in the form of magnets. Have you ever played with a pair of magnets, noticing how theyattract or repel each other depending on their relative orientation? There is an undeniableforce between a pair of magnets, and this force is without ”substance.” It has no mass, nocolor, no odor, and if not for the physical force exerted on the magnets themselves, it wouldbe utterly insensible to our bodies. Physicists describe the interaction of magnets in terms ofmagnetic fieldsin the space between them. If iron filings are placed near a magnet, they orientthemselves along the lines of the field, visually indicating its presence.439