An intrinsic semiconductor is electrically neutral. What is the electrical state of an extrinsic semiconductor?

In a pure silicon $(n_i = 10^{16}/m^3)$ crystal at $300\, K$,$10^{21}$ atoms of phosphorus are added per cubic meter. The new hole concentration will be

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?

If the ratio of the concentration of electrons to that of holes in a semiconductor is $\frac{7}{5}$ and the ratio of currents is $\frac{7}{4}$,then what is the ratio of their drift velocities?

In an $n$-type semiconductor, the Fermi energy level lies

In the energy band diagram of a material shown in the figure,the open circles and filled circles denote holes and electrons,respectively. The material is: