QUE: WHAT ARE INTRINSIC AND EXTRINSIC SEMICONDUCTOR ?

 SOL: INTRINSIC SEMICONDUCTOR These are completely pure semiconductor without any significant impurity present. These are also called undoped or i-type semiconductor. An insulator becomes conducting at high temperature or when irradiated with high energy radiation Because certain covalent bonds are broken which leads the formation of holes and electrons .example silicon

EXTRINSIC SEMICONDUCTOR / Impurity Defects In Covalent Crystals                                              This defect arises when some foreign particles( atoms or ions) are added to the lattice and they are present at the lattice sites or at the vacant interest.