Question

can anyone explain me zener diode practical?

Answer 1

A zener diode is basically designed to work during reverse bias. The diode will conduct just like an ordinary diode when it is forward biased. When it is reverse biased the zener diode begins to conduct when the voltage exceeds the zener breakdown voltage. Beyond this voltage the current increases, but the voltage across the diode remains constant. The P-N junction of the diode are heavily doped so that when electric field is applied electrons from the valance band of P type can easily jump to the conduction band N type material
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