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.

Analysis of Statement (A):
A Zener diode is a heavily doped semiconductor device designed to operate in the reverse breakdown region. When the reverse voltage applied across a Zener diode reaches its breakdown voltage, the current through it increases sharply while the voltage across the diode remains practically constant. This unique characteristic is utilized by connecting the Zener diode in parallel with a load in a reverse-biased configuration to regulate and maintain a stable output voltage. Therefore, Statement (A) is correct.

Analysis of Statement (B):
The potential barrier of a p-n junction depends on the type of semiconductor material used. For instance:
For a Germanium (Ge) junction, the potential barrier is approximately:
$V_{\mathrm{Ge}}=0.3\text{V}$
For a Silicon (Si) junction, the potential barrier is approximately:
$V_{\mathrm{Si}}=0.7\text{V}$
Since silicon is the most widely used semiconductor and its potential barrier is about 0.7 V, which lies well outside the 0.1 V to 0.3 V range, Statement (B) is incorrect.