Electrical Engineering - Voltage, Current and Resistance - Discussion

Electric charge carriers and ions are required to pass current from a substance. Insulators are non-conductor of electricity. Insulators cannot conduct electricity because they do not posses free electrons or charge carriers and ions. Ionic compounds in solid state are insulator. The forbidden energy gap is very large in insulators as compared to conduction band. Moreover, some insulators like ionic compounds can conduct electricity in molten or solution form due to the presence of free ions.

Insulator is a bad conductors of electricity. So it won't allows the electons in too it.

Insulator is a bad conductors of electricity ok. But the question is under normal condition only so then how it is possible? and what will happen obnormal condition?

What is Valence ?

Valence electron mean its contain a lot of free electron incase temperature increase electron move from valence band to conduction band.

I agree with my friend @Rajesekhar. Insulator is a bad conductor of electricity.

What about semiconductor?

Semiconductor is a materiel whose conductivity lies between conductor and insulator such as ge, si, etc.

Semiconductor can carries current?

Semiconductor won't conduct in normal conditions so that may be the correct answer.