a wire is conected to bulb does not glow ,whereas the filament of the bulb glows when same current flows through them...pls explain...urgent..!!!!!!!!!
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The wire are highly conducting are made up mainly of copper . The filament is made up of tungsten will a material glows when an electric current is passed because it heats up. This heating is directly proportional to the resistance offered to the current . Since copper is a highly conducting metal (= low resistance ) , it doesn't heat up to the point of melting of Wire . But tungsten offers more resistance thus it heats up glows also tungsten is chosen because it has the highest boiling point of all metals thus it wont melt away even when heated by an electric current but there is danger of snapping of the wire and thus the bulb wont work if the thin tungsten wire has broken then we say that the bulb has fused .
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