Easy MCQ +4 / -1 PYQ · JEE Mains 2020

If a semiconductor photodiode can detect a photon with a maximum wavelength of 400 nm, then its band gap energy is :

Planck’s constant h = 6.63 $\times$ 10–34 J.s. Speed of light c = 3 $\times$ 108 m/s

  1. A 1.5 eV
  2. B 2.0 eV
  3. C 3.1 eV Correct answer
  4. D 1.1 eV

Solution

$E = {{hc} \over \lambda }$ <br><br>= $${{6.63 \times {{10}^{ - 34}} \times 3 \times {{10}^8}} \over {400 \times {{10}^{ - 9}}}}$$ <br><br>= ${{1240} \over {400}}$ eV <br><br>= 3.1 eV

About this question

Subject: Physics · Chapter: Electronic Devices · Topic: Semiconductors

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