If the bandgap between the valence band and conduction band in a material is $5.0 \ eV$,then the material is

Which of the following substances has an energy gap $(E_g)$ greater than $3 \ eV$?

The forbidden energy gap in the energy bands of germanium at room temperature is about $......$ $eV$.

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):

Assertion $(A)$: When a wire of aluminium and another wire of silicon are heated from room temperature to $80^{\circ} C$,the conductivity of aluminium decreases and that of silicon increases.
Reason $(R)$: Aluminium has a positive temperature coefficient of resistivity and silicon has a negative temperature coefficient of resistivity.

At $0 \ K$ temperature,the valence band in semiconductors is .....