Q. Explain about Cathode Ray Tubes?

Cathode ray tube is the major technology on that televisions and monitors have been based.  CRT is a partially evacuated glass tube which is filled with inert gas at low pressure. A specially designed Cathode (negatively charged electrode) shoots beams of electrons at high speed in the direction of an anode (positively charged electrode) which imposes on screen that is coated with small phosphor coated dots of the three primary colours. This cathode is also known as an Electron Gun.  Actually there can be three separate guns for three colours (Red, Green and Blue) or one gun for all three.