The class of materials having the largest band gap in the following is

The energy gap of silicon is $1.14 \ eV$. The maximum wavelength at which silicon will begin absorbing energy is

Why does the resistivity of a semiconductor decrease with an increase in temperature?

This question has Statement $1$ and Statement $2$. Of the four choices given after the Statements,choose the one that best describes the two Statements.
Statement $1$ : $A$ pure semiconductor has a negative temperature coefficient of resistance.
Statement $2$ : On raising the temperature,more charge carriers are released into the conduction band.

The relation between the number of free electrons in semiconductors $(n)$ and its temperature $(T)$ is

Carbon, silicon, and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by $(E_g)_C$, $(E_g)_{Si}$, and $(E_g)_{Ge}$ respectively. Which one of the following relationships is true in their case?