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
