Question

The graph given below represents the $I-V$ characteristic curve of a Zener diode. Which part of the curve is most relevant for its operation as a voltage regulator ?

• A. $ab$
• B. $bc$
• C. $cd$
• D. $de$

Answer 1

The correct option is D $de$

As we know that Zener diode is based on reverse bias $p-n$ diode, so required region will be lies in the reverse bias zone.

If the voltage of reverse bias is greater than the Zener voltage, a breakdown condition is obtained, and in the given graph, we can clearly see that in part $de$, current is increasing, but voltage is nearly the same.

Therefore, portion $de$ of the characteristics curve is relevant for the operation of Zener diode as voltage regulator.

Hence, $\left(\text{D}\right)$ is the correct answer.