• # question_answer If the ratio of the concentration of electrons and holes in a semiconductor is 7/5 and the ratio of currents is 7/4, then what is the ratio of their driff velocities: A)  $\frac{7}{4}$                       B)  $\frac{5}{8}$C)  $\frac{4}{5}$                       D)  $\frac{5}{4}$

Given that   $\frac{{{n}_{e}}}{{{n}_{h}}}=\frac{7}{5}$ and $\frac{{{l}_{e}}}{{{l}_{h}}}=\frac{7}{4}$ $\frac{{{({{V}_{d}})}_{e}}}{{{({{V}_{d}})}_{h}}}=\frac{{{l}_{e}}}{{{l}_{h}}}\times \frac{{{n}_{h}}}{{{n}_{e}}}=\frac{5}{4}$