Question

why is the filament of the bulb kept in vaccume

Answer 1

An incandescent light bulb contains a thin wire filament (usually tungsten) that glows hot when an electric current is run through it. In the presence of oxygen, thefilament would burn up as a result of the high temperature. A glass bulb, then, is used to keep oxygen away from the filament.

Answer 2

bcz whn it is kept in air thn the filament burns up due to high temp.after coming in contact of oxygen..