Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • (a) Three photo diodes and  are made of semiconductors having

(a) Three photo diodes D_{1}, D_{2} and D_{3} are made of semiconductors having band gaps of 2.5 eV, 2 eV and 3 eV respectively. Which of them will not be able to detect light of wavelength 600 nm?
(b) Why photodiodes are required to operate in reverse bias? Explain.

 

 

 

 
 
 
 
 

Answers (1)

best_answer

(a) E=h{c/\lambda } is the energy of a photon of wavelength \lambda. Where, h is  the plank's constant and c is the speed of light in vacuum.

equating the values in the given equation:-

E=h{c/\lambda }

E=\frac{6.626\times 10^{-34/s}\times 3\times 10^{8m/s}}{600\times 10^{-9m}}

= 3.313\times 10^{-19}

= 3.313\times 10^{-19}\times \frac{1eV}{1.6\times 10^{-19}}

E=2.07 ev

The correct answer is D_{1} and D_{3},  Since the bandgap of diode D2 is less than the energy of the photon

(b) As it is easier to observe the change in current with the change in light intensity in reverse bias.

Posted by

rishi.raj

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE Class 10, 12 practical exams 2025 for compartment students from July 10; detailed guidelines issued
anam-khan

CBSE Central Sector Scheme of Scholarship 2025 applications open on scholarships.gov.in
anam-khan

CBSE Board 2025: Class 10th, 12th supplementary date sheet out; exams from July 15

Latest Question