Identify the sealed glass vacuum tube containing an electron beam that is focused on a phosphor-coated glass screen when light is emitted.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Cathode ray tube.
A CRT is a sealed glass vacuum tube with an electron gun at one end and a phosphor-coated screen at the other end. When the electron beam strikes the phosphor coating on the screen, it causes the phosphor to emit light, creating an image or display.
CRTs were commonly used in older television sets and computer monitors before the advent of flat-panel display technologies such as LCD, LED, and OLED.