Question

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

• A. $\frac{7}{4}$
• B. $\frac{5}{8}$
• C. $\frac{4}{5}$
• D. $\frac{5}{4}$

Answer 1

The correct option is D $\frac{5}{4}$

$\frac{n_e}{n_h}=$ $\frac{7}{5}$
$\frac{I_e}{I_h}=$ $\frac{7}{4}$
$\frac{(v_d{)}_e}{(v_d{)}_h}=$ $\frac{I_e}{I_h}\times$ $\frac{n_h}{n_e}=$ $\frac{5}{4}$