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Physics · 2022 · 2 marks
Semiconductor Electronics: Materials, Devices and Simple CircuitsSemiconductor Diode2 marksUnderstandvery short answer
CBSE 2022 · Region 2 · Set 2 · Q2
Briefly explain the working of a light emitting diode. Mention its two uses.
Briefly explain the working of a light emitting diode. Mention its two uses.
Marking-scheme solution
When the diode is forward biased, electrons are sent from n-side to p-side and holes are sent from p-side to n-side. At the junction the concentration of minority carriers increases. Thus, at the junction, the excess minority carriers recombine with majority carriers and energy is released in the form of photons.
Uses:-
1) Remote controls
2) Burglar Alarm System
3) Optical Communication
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CBSE Class 12 Physics past-paper question from the 2022 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.