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.

The correct option is: (A) is correct and (B) is incorrect.

Let us carefully evaluate both statements step-by-step:

Analyzing Statement (A): A Zener diode is connected in reverse bias, when used as a voltage regulator.

This statement is correct. A Zener diode is a specially designed, heavily doped semiconductor device intended to operate in the reverse breakdown region (often called the Zener region). When connected in reverse bias, once the applied voltage reaches the characteristic Zener breakdown voltage, the diode begins to conduct significant current. In this state, the voltage drop across the Zener diode remains remarkably constant over a wide range of reverse currents. This property of maintaining a steady voltage regardless of current fluctuations is exactly what makes it function perfectly as a voltage regulator.

Analyzing Statement (B): The potential barrier of p-n junction lies between 0.1 V to 0.3 V.

This statement is incorrect. The built-in potential barrier of a p-n junction diode depends heavily on the specific semiconductor material used to manufacture it, as well as the temperature. While it is true that the potential barrier for a Germanium (Ge) p-n junction is approximately 0.2 V to 0.3 V, Germanium is just one type of semiconductor. The most widely used semiconductor in modern electronics is Silicon (Si). For a standard Silicon p-n junction at room temperature, the potential barrier is significantly higher, typically around 0.7 V. Because the statement rigidly restricts the potential barrier range to 0.1 V to 0.3 V without accounting for Silicon (0.7 V), the generalization is false.

Therefore, we can conclusively determine that Statement (A) is correct and Statement (B) is incorrect.