Identify the correct statements among the following.(A) At 0 K, the r…

The correct answer is Option (3) → (A), (B) and (D) only

(A) At 0 K, the resistance of a semiconductor is infinite. — Correct. At 0 K the valence band is full and the conduction band empty, so there are no free charge carriers and the resistance is infinite.

(B) In an n-type semiconductor, the electron concentration is approximately equal to the concentration of donor atoms. — Correct. Each donor atom gives one electron to the conduction band, and these far outnumber the thermally generated electrons, so \( n_e \approx N_D \).

(C) In p-type semiconductors, the acceptor levels lie near the conduction band. — Incorrect. The acceptor levels lie just above the valence band, which is why electrons from the valence band can jump into them and leave holes.

(D) In n-type semiconductors, the charge carriers are both electrons and holes. — Correct. Electrons are the majority carriers and the thermally generated holes are the minority carriers, so both carry the current.

So the correct statements are (A), (B) and (D), which is Option (3).

NCERT (2026-27):
Intrinsic Semiconductor – “… An intrinsic semiconductor will behave like an insulator at T = 0 K as shown in Fig. 14.6(a).”

Extrinsic Semiconductor – “… Hence in an extrinsic semiconductor doped with pentavalent impurity, electrons become the majority carriers and holes the minority carriers. These semiconductors are, therefore, known as n-type semiconductors.”

Extrinsic Semiconductor – “… At room temperature, most of the donor atoms get ionised but very few (~10¹²) atoms of Si get ionised. So the conduction band will have most electrons coming from the donor impurities, as shown in Fig. 14.9(a).”

Extrinsic Semiconductor – “… Similarly, for p-type semiconductor, the acceptor energy level E_A is slightly above the top E_V of the valence band as shown in Fig. 14.9(b).”