Facebook
Google
GitHub
LinkedinBasic Electricity
Wire Types and Sizes
16 questions By Tony R. Kuphaldt
-
Question 1 of 16
Most electrical wire is covered in a rubber or plastic coating called insulation. What is the purpose of having this “insulation” covering the metal wire?
Reveal answerThe purpose of insulation covering the metal part of an electrical wire is to prevent accidental contact with other conductors of electricity, which might result in an unintentional electric current through those other conductors.
Notes:Not only is this question practical from the standpoint of understanding circuit function, but also from the perspective of electrical safety. Why is it important for wires to be insulated? Are overhead power lines insulated like the wires used in classroom projects? Why or why not? How were electrical wires insulated before the advent of modern plastics technology?
-
Question 2 of 16
In the early days of electrical wiring, wires used to be insulated with cotton. This is no longer accepted practice. Explain why.
Reveal answerCotton, like many natural fibers, is an electrical insulator . . . until it becomes wet!
Notes:This question affords the opportunity to discuss electrical safety with regard to clothing (often made of cotton). Does dry clothing offer insulation to electricity like the old-style cotton wire insulation? Can cotton clothing be trusted to insulate you safely from hazardous voltage?
-
Question 3 of 16
Electrical wire is often rated according to its cross-sectional diameter by a gauge scale. Which is the larger-diameter wire size, 14 gauge or 8 gauge?
Reveal answer8 gauge is the larger diameter.
Notes:For students familiar with shotguns, the methodology of the wire gauge scale makes sense. For just about everyone else, the gauge scale seems “backward.”
