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Question Bank [ 2022 ] — Physics STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 SciencePhysicsQuestion Bank [ 2022 ]1 Mark
MCQ
A LED emits visible white light when its ______  
  • A
    junction is reversed-biased.
  • B
    depletion layer widens.
  • ✓
    holes and electrons recombine.
  • D
    junction becomes hot.
✓

Answer

Correct option: C.
holes and electrons recombine.
A LED emits visible white light when its holes and electrons recombine.

Explanation:

LED is a semi-conductor source of light which emits light when current flows through it. When electrons in semiconductors recombine with electron holes, releasing energy, in the form of photons.

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