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14. Semicondutor electronics — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics14. Semicondutor electronics1 Mark
MCQ
A light emitting diode $(LED)$ is fabricated using GaAs semiconducting material whose band gap is $1.42 \mathrm{eV}$. The wavelength of light emitted from the $LED$ is:
  • A
    $650 \mathrm{~nm}$
  • B
    $1243 \mathrm{~nm}$
  • ✓
    $875 \mathrm{~nm}$
  • D
    $1400 \mathrm{~nm}$
✓

Answer

Correct option: C.
$875 \mathrm{~nm}$
c
$\lambda=\frac{1240}{1.42}=875 \mathrm{~nm}$ $(Approx)$

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