Question

Zener breakdown in a semiconductor diode occurs when

• A. forward current exceeds certain value
• B. reverse bias exceeds certain value
• C. forward bias exceeds certain value
• D. potential barrier is reduced to zero

Answer 1

The correct option is B reverse bias exceeds certain value

When reverse bias is increased, the electric field at the junction also increases. At some stage the electric field breaks the covalent bond, thus the large number of charge carriers are generated.This is called Zener breakdown.
So, the answer is reverse bias exceeds certain value.