Question

Why is wire covered with insulating material in the circuit​

Answer 1

bcoz wire without insulator got short circuit

Answer 2

Answer:

Question 1

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?

Hide Answer

The purpose of insulationcovering 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

In the early days of electrical wiring, wires used to be insulated with cotton. This is no longer accepted practice. Explain why.

Hide Answer

Cotton, 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

Electrical wire is often rated according to its cross-sectional diameter by a gaugescale. Which is the larger-diameter wire size, 14 gauge or 8 gauge?

Hide Answer

8 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.”

Question 4

In the Unites States of America, an organization known as the National Fire Protection Association, or NFPA, publishes an important set of standards called the National Electrical Code. What type of information is contained in this set of standards?

Hide Answer

The NEC contains standards regarding the installation of electrical power circuits (primarily), but also communications and control circuitry. It is the predominant reference for construction electrical work of all types.

Notes:

NEC code books are rather large, so students may feel inclined to limit their answers to what is included in the “Answer” for this question. However, you should challenge them to look deeper into an NEC book and discover the wealth of information contained therein.

Specifically, ask them to describe some of the “Article” topics typically found in an NEC book.