What is the most useful characteristic of a Zener diode?
A constant current drop under conditions of varying voltage
A constant voltage drop under conditions of varying current✓Bonne réponse
A negative resistance region
An internal capacitance that varies with the applied voltage
Explication
Operated in reverse breakdown, this reference diode holds its terminal voltage nearly constant while the current through it varies over a wide range, which is what makes it useful as a voltage reference or shunt regulator. A negative-resistance region belongs to the tunnel diode and a voltage-dependent internal capacitance to the varactor.