In a reverse-biased p-n junction, when the applied bias voltage is equal to the breakdown voltage, then:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → current increases sharply.
Under reverse bias only a small current flows, carried by minority carriers; it is almost independent of the voltage. When the reverse voltage reaches the breakdown voltage, covalent bonds are broken (Zener breakdown) or carriers multiply by collisions (avalanche breakdown), and the reverse current increases sharply while the voltage stays almost constant. This is the principle of the Zener diode used as a voltage regulator.
NCERT (2026-27):
p-n Junction Diode Under Reverse Bias – “… The current under reverse bias is essentially voltage independent upto a critical reverse bias voltage, known as breakdown voltage (\( V_{br} \)). When \( V = V_{br} \), the diode reverse current increases sharply. Even a slight increase in the bias voltage causes large change in the current.”