In n-type semiconductors, A are the majority charge carriers and B are the minority charge carriers. Here A and B are
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A- electrons ; B- holes
An n-type semiconductor is made by doping pure silicon or germanium with a pentavalent impurity. Each impurity atom gives one free electron, so the conduction is mainly by electrons.
The majority carriers are therefore the electrons, while the thermally generated electron-hole pairs leave a small number of holes as the minority carriers. So A is electrons and B is holes.
Option (1) A- electrons ; B- protons — Incorrect. Protons are in the nucleus and are not charge carriers in a semiconductor.
Option (2) A- protons ; B- electrons — Incorrect. Protons are not charge carriers, and electrons are the majority, not the minority, carriers.
Option (3) A- electrons ; B- holes — Correct. Majority carriers are electrons and minority carriers are holes.
Option (4) A- holes ; B- electrons — Incorrect. This is the arrangement for a p-type semiconductor.
NCERT (2026-27):
Extrinsic Semiconductor – “… Thus, with proper level of doping the number of conduction electrons can be made much larger than the number of holes. 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.”