First slide

Types of semiconductors

Question

A n-type silicon sample of width $4 x 10^{- 3} m$ , thickness and length $6 \times 10^{- 2} m$ carriers a current of 4.8 mA, when the voltage is applied across the length of the sample. The free electron density is $10^{22} m^{- 3}$

Moderate

A

the current density is $20 A / m^{2}$
B

the drift speed is 1.25cm/s
C

the time taken by electrons to travel the full length of the sample is 4.8sec
D

all options are correct

Solution

$C u r r e n t d e n s i t y = \frac{i}{A} = \frac{4.8 \times 10^{- 3}}{4 \times 10^{- 3} \times 6 \times 10^{- 2}} = 20 A / m^{2}$
$D r i f t s p e e d = V_{d} = \frac{i}{A n e} = \frac{20}{10^{22} \times 1.6 \times 10^{- 19}} = 1.25 \times 10^{- 2} m / s$
$T i m e = t = \frac{l}{V_{d}} = \frac{6 \times 10^{- 2}}{1.25 \times 10^{- 2}} = 4.8 \sec$

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