Minority carriers in a $p$-type semiconductor are

Which of the following statements is incorrect?

The length of a germanium rod is $0.928 \ cm$ and its area of cross-section is $1 \ mm^2$. If for germanium $n_i = 2.5 \times 10^{19} \ m^{-3}$,$\mu_h = 0.15 \ m^2 V^{-1} s^{-1}$,and $\mu_e = 0.35 \ m^2 V^{-1} s^{-1}$,then the resistivity is:

In a pure silicon, the number of electrons and holes per unit volume is $1.6 \times 10^{16} \,m^{-3}$. If silicon is doped with Boron in a way that the hole density increases to $4 \times 10^{22} \,m^{-3}$, then the electron density in the doped semiconductor will be:

If the ratio of the number density of electrons to the number density of holes in a semiconductor is $7/5$ and the ratio of their currents is $7/4$,what is the ratio of their drift velocities?

In an $n$-type semiconductor,the free electrons donated by the impurity atoms occupy energy levels in: