In an insulator,the forbidden energy gap between the valence band and conduction band is of the order of

When the temperature of a silicon sample is increased from $27^\circ C$ to $100^\circ C$,the conductivity of silicon will be

If the lattice constant of this semiconductor is decreased,then which of the following is correct?

On heating a semiconductor:

When a semiconductor is heated,its resistance

The band diagrams for three different semiconductors are shown in the figure below. Starting from the left to the right,identify the types of semiconductors they represent.