Question

The fluorescence of the glass (discharge) tube at very low pressure is characteristic of ________ .

• A. the phosphors in the material of the glass
• B. the gas used in the tube
• C. the cathode
• D. all the above

Answer 1

The correct option is A the phosphors in the material of the glass

Fluorescence is the emission of light by a substance that as absorbed light as other electromagnetic radiation. It occurs due to presence of phosphorous in the metal tube. Because phosphorous is a material that glows when exposed to electrical energy. Because actual conversion of electrical to light energy takes place on display screen when electron strike phosphorous.