In a semiconductor,

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

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

Statement-$1$: The temperature coefficient of resistance of an intrinsic semiconductor is negative.
Statement-$2$: As temperature increases,more charge carriers are released into the conduction band.

The temperature dependence of resistances of $Cu$ and undoped $Si$ in the temperature range $300-400 \ K$ is best described by:

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