Question

How is the number of electrons and number of holes related in an intrinsic conductor?
(A) 2 (No. of electron) =No. of holes
(B) No. of electrons=No. of holes
(C) No. of electrons=4(No. of holes)
(D) No. of electrons=3(No. of holes)

Answer 1

HintIntrinsic conductors are pure conductors. The Fermi level lies at the center of the conduction band and valence band. Free electrons are obtained when an electron leaves its place and creates a hole. So, there is one hole produced because of one free electron. They have equal numbers of electrons and holes.

Complete step-by-step solution
A hole is considered as a seat of positive charge, having magnitude of charge equal to that of an electron.
A pure semiconductor is called an intrinsic conductor. It has thermally generated current carriers. They have four electrons in the outermost orbit of an atom and atoms are held by covalent bond. Free electrons and holes are both charge carriers and the number of electrons in the conduction band is equal to the number of holes in the valence band. Eg: Silicon and germanium.

Hence, the correct option is B.

Note: Extrinsic conductors are impure. N-type and P-type are the two types under them. N-type semiconductors have electrons as their majority charge carriers. P-type semiconductors have holes as their majority semiconductors.