(a) On what principle does lighting in a fluorescent tube operate? (b) State two factors which determine the colour of light produced in a fluorescent tube.
(a) On what principle does lighting in a fluorescent tube operate?
(b) State two factors which determine the colour of light produced in a fluorescent tube.
(a) Principle of a fluorescent tube
A fluorescent tube works on the principle of fluorescence. An electric discharge is passed through mercury vapour in the tube, which emits ultraviolet (UV) radiation. This UV radiation strikes the fluorescent (phosphor) powder coating the inside wall of the tube, causing it to fluoresce and give out visible light.
(b) Two factors that determine the colour of the light produced
The nature (chemical composition) of the fluorescent powder (phosphor) coating the inside of the tube.
A fluorescent tube works on the principle of fluorescence. An electric discharge is passed through mercury vapour in the tube, which emits ultraviolet (UV) radiation. This UV radiation strikes the fluorescent (phosphor) powder coating the inside wall of the tube, causing it to fluoresce and give out visible light.
(b) Two factors that determine the colour of the light produced
The nature (chemical composition) of the fluorescent powder (phosphor) coating the inside of the tube.