Question
Download Solution PDFThe light given off by the phosphor during exposure to the electron beam is known as
Answer (Detailed Solution Below)
Option 1 : Fluorescence
Detailed Solution
Download Solution PDFThe correct answer is Fluorescence.
Key Points
- Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation.
- It is a form of luminescence.
- In a cathode ray tube (CRT) or other similar devices, when the phosphor coating is struck by the electron beam, it emits visible light through the process of fluorescence.
- This emission of light occurs almost instantaneously with the exposure to the electron beam.
- Fluorescence ceases almost immediately when the excitation source (electron beam) is removed.
- This characteristic makes it suitable for applications requiring quick response times.
Additional Information
- Phosphorescence, on the other hand, involves a delayed emission of light and continues to glow even after the excitation source is removed.
- Persistence refers to the duration the screen continues to emit light after the electron beam has moved on.
- Retracing is the process where the electron beam returns to the beginning of the next line or frame in a CRT display.