Electronic Devices - Semiconductors - Discussion

The insulator has no charge carrier. So the answer should be D.

Yes, @Kalai is right.

The conductivity of any material is inversely proportional its resistivity. An insulator like nylon, polyethylene and wood have some degree of conductivity. Conductors have different conductivity so some can be comparably insulators. Nylon and polyethylene can be made to transfer electrons by rubbing against with a special rod. Once the electrons are able to move a small amount of current is recorded which differs from materials hence conduction occurs.

We can not say that all materials have the same electron, conduction and depletion layer hence the difference.

Insulators are not meant to have free electrons. Free electrons leads to conductivity whether in small amounts or big. That's why some conductors are more effective than others. So there is no reason for a n insulator to have free electrons since it does not conduct electricity.

The flow of the electrons is called as current. If there is very less amount of the electrons the current flow will be decreased to low or zero.

Option C is correct because there is no perfect insulator.

The answer should be d D because an insulator hasn't any free electron.

Answer D is correct, In insulator, the energy gap is very large approx 5ev. Electrons can't jump from valence band to conduction band so conduction band is completely empty. If temp increase the device will same.

Conductor have large free electrons.

Semiconductor have few free electrons.

Insulators have no free electrons.