Fermi level in the case of intrinsic semiconductor lies

State anyone difference between the energy band diagram of conductors and that of insulators.

On the basis of band theory, distinguish among insulator, semiconductor, and conductor of electricity.

The band gaps of an insulator, semiconductor and conductor are respectively ${\mathrm{E}}_{{\mathrm{g}}_1,} {\mathrm{E}}_{{\mathrm{g}}_2} \mathrm{and} {\mathrm{E}}_{{\mathrm{g}}_3}$.The relationship between them can be given as:

State the conditions required to achieve laser action.

Match the List I with List II

Choose the correct answer from the options given below:

The chromium ions doped in the ruby rod: