Question: 23. Consider the following statements (A) and (B) and identify the correct answer.
(A) A zener diode is connected in reverse bias, when used as a voltage regulator.
(B) The potential barrier of p-n junction lies between 0.1 V to 0.3 V .
(1) (A) and (B) both are correct.
(2) (A) and (B) both are incorrect.
(3) (A) is correct and (B) is incorrect.
(4) (A) is incorrect but (B) is correct.
Answer: Option (3)
Explanation:
A Zener diode is used as a voltage regulator by operating it in the reverse bias condition.
In this region, when the reverse voltage reaches the Zener breakdown voltage,
the diode maintains a nearly constant voltage across its terminals.
Hence, statement (A) is correct.
The potential barrier of a p-n junction depends on the material of the semiconductor.
For silicon, it is approximately 0.7\,\text{V}, and for germanium, it is about 0.3\,\text{V}.
Therefore, the statement that the potential barrier lies between 0.1\,\text{V} to 0.3\,\text{V} is incorrect.
Thus, statement (A) is correct and statement (B) is incorrect,
and the correct answer is Option (3).