Distinguish between intrinsic and extrinsic semiconductors.

Answer

Intrinsic and extrinsic semiconductors can be differentiated as follows:

Intrinsic	Extrinsic
1. It is a pure semiconductor and no impurities are added to it.	1. It is prepared by doping a small quantity of impurity atoms to the pure semiconducting material.
2. Number of free electrons in conduction band is equal to the number of holes in valence band.	2. Number of free electrons and holes vary in n-type and p-type semiconductor. There is excess of electrons in n-type and excess of holes in p-type.
3. It's electrical conductivity is low.	3. Electrical conductivity is high.
4. Electrical conductivity is solely a function of temperature.	4. Electrical conductivity depends upon temperature as well as on the quantity of dopants.