Band theory of Solids

In an insulating material..

I.The valence band is filled

II. the conduction band is filled

III. the valence band is empty

IV. the conduction band is empty

• I only

• ii and III

• I and IV

• I and II

A material with a relatively large gap between its valence band and conduction band would be expected to be __

• a good conductor

• esily melted

• a poor conductor

• in a crystal state

What is the approximate energy gap between the valance and conduction band of a semiconductor?

• 0 eV

• 1 eV

• 5 eV

• 10 eV

A material that conducts electricity well tends to have___

• no valance electrons

• partially filled bands

• completely filled bands

• conduction and valance bands that are far apart

How can the conductivity of a semi-conductor be increased?

• apply a magnetic field

• apply an electric field

• increase the temperature

• apply an electric field and increasing the temperature

The energy level diagram shown applies to ___

• a conductor

• an insulator

• a semi-conductor

• an isolated atom

True or false

Band theory explains electric conduction in terms of energy bands and forbidden gaps.

• True

• False