Prabin Kalikote

A thin and long tungsten wire is used in an electricbulb because it has very high resistivity and has a veryhigh melting point. So, it doesn't melt even if thelight bulb has a high temperature.

We know, inert gas doesn't take part in any reactiondue to its stable state of electronic configuration. As aresult, using its property, to avoid chemical reaction inside bulb even in extreme temperature inert gasis used to fill the electric bulb.

We know that the birds don't touch the earth's surfacewhile sitting on power lines. So, the current that flowsto their body and flows back again to the wire. Therefore,the bird doesn't get any shock. Hence,birds are found sittingon high voltage transmission lines.

We know that neutral wire (earthing wire) carries the leakedcurrent to the earth. If we touch the earthing wirealso, the current flows to ourbody and returns to thewire, and goes to the ground to be neutralized. So, wedon't feel shocked even if we touch a neutral wire.

We know, filament lamp converts only 10% of electricalenergy to light energy but a fluorescent lamp converts30% of electrical energy into light energy. So, afluorescent lamp of 40W is better than a filamentlamp of 40 W.

DC is not used in a transformer because it cannotchange the electromotive force of DC because themagnitude of the DC doesn't change. So, AC is usedas its magnitude and polarity change.

We know, electric current flows from phone wire to thepower load. So, to disconnect or block the current rightat phase wire during the case of overload, a fuse isconnected to a phase wire.