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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctEasyCalculation

JEE Main 22 July 2021, Shift 2, Physics Q18

Question 18 of 90 in this shift, Physics question 18 of 30, Section A.

Consider a situation in which reverse biased current of a particular P-N junction increases when it is exposed to a light of wavelength ≤621\leq 621 nm. During this process, enhancement in carrier concentration takes place due to generation of hole-electron pairs. The value of band gap is nearly.
  1. (1)4 eV
  2. (2)2 eVOfficial answer
  3. (3)1 eV
  4. (4)0.5 eV

Official answer

Option 2

NTA final key.

Chapter
Semiconductor Electronics: Materials, Devices and Simple Circuits
Topic
Semiconductor Diodes
Idea tested
Photodiode Reverse Bias Rationale

Same idea in other shifts

Asked 2× in all
  1. 25 Jun 2022, Shift 1 · Q47The photodiode is used to detect the optical signals. These diodes are preferably operated in reverse biased mode because :EasySingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.