How does an intrinsic semiconductor behave at $0 \ K$?

The energy gap of a semiconductor is $1.10 \ eV$. The maximum wavelength in $\mathring{A}$ at which it starts energy absorption will be (approximately):

In which of the following is an ionic bond present?

Assertion: If the temperature of a semiconductor is increased,then its resistance decreases.
Reason: The energy gap between the conduction band and the valence band is very small.

On the basis of which principle are the band diagrams of solids classified into different types?

The resistivity $(\rho)$ of a semiconductor varies with temperature. Which of the following curves represents the correct behavior?