question_answer

In breakdown region, a zener diode behaves as a

A)  constant current source

B)  constant voltage source

C)  constant resistance source

D)  constant power source

Correct Answer: B

Solution :

When the reverse voltage across a zener diode exceeds the breakdown voltage \[{{V}_{Z}},\] the current increases very sharply. In this region, the curve is almost vertical. It means voltage across zener diode is constant at \[{{V}_{Z}},\] even though the current through it changes. Therefore, a zener diode behaves as a constant voltage source.