Multiple choice An ordinary tubelight used for lighting purposes contains fluorescent materials and an inert gas one filament, reflective material and mercury vapour fluorescent material and mercury vapour two filaments, flurescent material and mercury vapour Reveal answer Fill a bubble to check yourself D Correct answer Explanation A tubelight contains two filaments (for starting), fluorescent material coating (to convert UV to visible light), and mercury vapor (to produce UV when ionized).