Match List-I with List-II
| List-I | List-II |
| (A) An intrinsic semiconductor material | (I) Prepared by doping a small quantity of impurity atoms to pure semiconductor material |
| (B) An extrinsic semiconductor | (II) no impurity atoms are added |
| (C) Electrical conductivity of an intrinsic semiconductor | (III) depends on the concentration of impurity atoms doped in it |
| (D) Electrical conductivity of extrinsic semiconductor | (IV) is low |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
An intrinsic semiconductor is pure; an extrinsic semiconductor is doped, and its conductivity is controlled by the doping.
(A) An intrinsic semiconductor material — this matches (II) no impurity atoms are added. “Intrinsic” means the pure semiconductor itself.
(B) An extrinsic semiconductor — this matches (I) Prepared by doping a small quantity of impurity atoms to pure semiconductor material. Doping with a trivalent or pentavalent impurity makes the semiconductor extrinsic.
(C) Electrical conductivity of an intrinsic semiconductor — this matches (IV) is low. At room temperature only a few electron–hole pairs are thermally generated.
(D) Electrical conductivity of extrinsic semiconductor — this matches (III) depends on the concentration of impurity atoms doped in it. Each dopant atom supplies one carrier, so more doping means more carriers.
NCERT (2026-27):
Extrinsic Semiconductor – “The conductivity of an intrinsic semiconductor depends on its temperature, but at room temperature its conductivity is very low. … When a small amount, say, a few parts per million (ppm), of a suitable impurity is added to the pure semiconductor, the conductivity of the semiconductor is increased manifold. Such materials are known as extrinsic semiconductors or impurity semiconductors.”
Summary – “… 5. Pure semiconductors are called ‘intrinsic semiconductors’.”
Summary – “… 6. The number of charge carriers can be changed by ‘doping’ of a suitable impurity in pure semiconductors. Such semiconductors are known as extrinsic semiconductors.”