When a battery is connected to a $P$-type semiconductor with a metallic wire,the current in the semiconductor (predominantly),inside the metallic wire,and inside the battery is due to which charge carriers respectively?

The charge on a hole is equal to the charge of

$A$ semiconductor doped with a donor impurity is

Out of the following impurities, which impurity is not a trivalent?

In pure silicon,the electron-hole concentration at $T = 300 \ K$ is $7 \times 10^{15} \ m^{-3}$. Antimony is added as an impurity to silicon at a rate of $1$ atom per $10^7 \ Si$ atoms. Assume that half of the impurity atoms contribute their electrons to the conduction band. Calculate the factor by which the number of charge carriers increases. Given: the number density of silicon atoms is $5 \times 10^{28} \ m^{-3}$.

When arsenic is added as an impurity to silicon,the resulting material is