Question

In a zener diode, the reverse bias voltage is $3V$ and the width of the depletion region is $300\overset{0}{\mathop{A}}\,$, the electric field intensity will be ………..$\dfrac{V}{m}$
$\begin{align}
  & A{{.10}^{6}} \\
 & B{{.10}^{4}} \\
 & C{{.10}^{8}} \\
 & D{{.10}^{-2}} \\
\end{align}$

Answer 1

Hint: A zener diode is a semiconductor equipment which is made up of silicon. It will allow current to flow in either a forward or reverse direction. This type of diode is made up of a heavily doped p-n junction which is developed due to the conduction occurring in the reverse direction when a particular voltage has been reached. In this the magnitude of the barrier electric field for a zener diode can be found by dividing the reverse bias voltage with the width of the depletion region. These details may help you to solve this question.

Formula Used:
$E=\dfrac{V}{d}$

Complete step-by-step answer:
First of all let us take a look at the value which are mentioned in the question,
The reverse bias voltage of the given zener diode is given as,
$V=3V$
The width of the depletion region in this zener diode has been mentioned as,
$d=300\times {{10}^{-10}}m$
Therefore as we all know, the magnitude of the barrier electric field can be found as,
$E=\dfrac{V}{d}$
Substituting the given values in it,
$E=\dfrac{3V}{300\times {{10}^{-10}}}={{10}^{8}}\dfrac{V}{m}$
This has been mentioned as the third option in the question. Therefore the correct answer is option C.

Note: Zener diodes are helpful in voltage regulation. It is used as the reference elements, surge suppressors, and also in switching applications and clipper circuits. The resistor which is connected in series limits the current flow through the diode and it will reduce the extra voltage if the diode is conducting. The zener diodes are made as reverse biased diodes which can actually operate in a breakdown. When the reverse bias voltage increases, Zener diodes will continue to conduct a fixed amount of current known as the saturation current. This happens only up to the reach of a certain voltage.