(a) Explain how neon signs can be produced.
(b) State two factors on which the colour of light from a fluorescent tube depend.
Explanation
(a) A discharge tube at very high p.d. filled with neon and evacuated to a very low pressure of about 5mm will produce a discharge between the electrodes with a characteristic colour.
(b) The colour depends on;
– nature of the gas in the tube.
-nature of coating inside the tube