Match the LIST-I with LIST-II
| LIST-I | LIST-II | ||
|---|---|---|---|
| (Material) | (Example) | ||
| A. | Intrinsic semiconductor | I. | Carbon (diamond) |
| B. | Trivalent dopant | II. | Arsenic |
| C. | Insulator | III. | Germanium |
| D. | Pentavalent dopant | IV. | Indium |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A-III, B-IV, C-I, D-II
Each example is placed by its valence or its band gap.
(A) Intrinsic semiconductor — this matches (III) Germanium. Pure germanium (group 14) is an intrinsic semiconductor with a small band gap of about 0.7 eV.
(B) Trivalent dopant — this matches (IV) Indium. Indium is in group 13, so it has three valence electrons and acts as an acceptor.
(C) Insulator — this matches (I) Carbon (diamond). Diamond has a large band gap of about 5.4 eV, so almost no electrons reach the conduction band.
(D) Pentavalent dopant — this matches (II) Arsenic. Arsenic is in group 15, with five valence electrons, and acts as a donor.
NCERT (2026-27):
Extrinsic Semiconductor – “… There are two types of dopants used in doping the tetravalent Si or Ge:
(i) Pentavalent (valency 5); like Arsenic (As), Antimony (Sb), Phosphorous (P), etc.
(ii) Trivalent (valency 3); like Indium (In), Boron (B), Aluminium (Al), etc.”
Extrinsic Semiconductor – “… For C (diamond), Si and Ge, the energy gaps are 5.4 eV, 1.1 eV and 0.7 eV, respectively.”
Intrinsic Semiconductor – “… Example 14.1 C, Si and Ge have same lattice structure. Why is C insulator while Si and Ge intrinsic semiconductors?”