First slide

Classification of semi-conductors

Question

The contribution in the total current flowing through a semiconductor due to electrons and holes are ¾ and ¼ , respectively. If the drift velocity of electrons is 5/2 times that of holes at this temperature, then the ratio of concentration of electrons and holes is

Moderate

A

6 : 5
B

5 : 6
C

3 : 2
D

2 : 3

Solution

As we know current density J = nqv
$\begin{array}{l} \Rightarrow J_{e} = n_{e} {qv}_{e} and J_{h} = n_{h} {qv}_{h} \\ \Rightarrow \frac{J_{e}}{J_{h}} = \frac{n_{e}}{n_{h}} \times \frac{v_{e}}{v_{h}} \Rightarrow \frac{3 / 4}{1 / 4} = \frac{n_{e}}{n_{h}} \times \frac{5}{20} \Rightarrow \frac{n_{e}}{n_{h}} = \frac{6}{5} \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App