semiconductor-electronics--materials-devices-and-simple-circuits Question 39

Question: Q. 5. Explain with the help of suitable diagram, the two processes which occur during the formations of a $p-n$ junction diode. Hence define the terms (i) depletion region and (ii) potential barrier.

(b) Draw a circuit diagram of a $p-n$ junction diode under forward bias and explain its working.

[CBSE Comptt. 2018]

$\begin{array}{lr}\text {

Show Answer

Solution:

Ans. (a) Explaining the two processes } & 1+1 \ \text { Defining the two terms } & 1 / 2+1 / 2\end{array}$

(b) Circuit diagram

Working

1

(a) The two important processes are diffusion and drift. Due to concentration gradient, the electrons diffuse from the $n$ side to the $p$ side and holes diffuse the $p$ side to the $n$ side.

$1 / 2$ Electron drift $\xrightarrow{\longleftrightarrow}$ Electron diffusion

Due to the diffusion, an electric field develops across the junction. Due to the field, an electron moves from the $p$-side. The flow of the charge carriers due to the electric field, is called drift. $1 / 2$

(i) Depletion region :

It is the space charge region on either side of the junction, that gets depleted of free charges. is known as the depletion region.

(ii) Potential Barrier :

The potential difference, that gets developed across the junction and opposes the diffusion of charge carries and brings about a condition of equilibrium, is known as the barrier potential. 1/2

(b) Try yourself similar to Q. 5 SAT Question-II

[CBSE Marking Scheme 2018]

OSWAAL LEARNING TOOLS

For Suggested Online Videos

Visit : https://qrgo.page.link/v6rh6

Visit : https://qrgo.page.link/iK7Jd

Or Scan the Code

Or Scan the Code

UNIT - X



Table of Contents

NCERT Chapter Video Solution

Dual Pane