Bonding in a germanium crystal (semiconductor) is:

GaAs is

For a germanium crystal,the forbidden energy gap in joules is:

$A$ copper strip and a germanium strip are cooled to $80 \ K$ from room temperature. The resistance of:

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.

In a semiconductor,the separation between the conduction band and the valence band is of the order of $... \, eV$.