Discussion
Light Emitting Diode (LED) work on principle of
Answer: A
An LED works on electroluminescence.
In a light emitting diode, a forward voltage drives electrons across a p-n junction. When they recombine with holes they fall to a lower energy level and give out the difference as light. Light produced directly by an electric current in a material in this way is electroluminescence.
A laser relies on stimulated emission and an optical cavity, which an ordinary LED does not have. Thermionic emission is the release of electrons from a hot filament, as in a vacuum tube. The photoelectric effect is the reverse process, light releasing electrons, and is the principle of a photodiode or solar cell.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development