JEE Main 2023 · 1 February · morning · Single correct · +4 / −1
Match List I with List II:
Choose the correct answer from the options given below :
| List I | List II | ||
|---|---|---|---|
| A. | Intrinsic semiconductor | I. | Fermi-level near the valence bond |
| B. | n-type semiconductor | II. | Fermi-level in the middle of valence and conduction band. |
| C. | p-type semiconductor | III. | Fermi-level near the conduction band |
| D. | Metals | IV. | Fermi-level inside the conduction band |
- (a) A-III, B-I, C-II, D-IV
- (b) A-II, B-I, C-III, D-IV
- (c) A-I, B-II, C-III, D-IV
- (d) A-II, B-III, C-I, D-IV
Answer and solution
Answer (d) A-II, B-III, C-I, D-IV
Solution
Physics sir · 3 steps
Follow the majority carriers: the Fermi level shifts towards the band where they live.
- Meaning of Fermi level. The Fermi level is the energy at which the chance of finding an electron is one half. More free electrons push it up towards the conduction band. More holes push it down towards the valence band.
Material Majority carriers Fermi level Match A. Intrinsic electrons = holes in the middle of the gap II B. n-type electrons (from donors) near the conduction band III C. p-type holes (from acceptors) near the valence band I D. Metals free electrons, no gap inside the conduction band IV - Why metals differ. In a metal the conduction band is partly filled or overlaps the valence band. So the Fermi level lies inside a band, not in a gap. In List II, "valence bond" means the valence band.
- So. The matching is A-II, B-III, C-I, D-IV, which is option (d).
The idea to keep. Electrons pull the Fermi level up and holes pull it down. Intrinsic sits midway, n-type near the conduction band, p-type near the valence band, and metals have it inside the conduction band.
Answer from the NTA final answer key. Solution by PrepWiser.