What happens during regulation action of a Zener diode?
A. The current in and voltage across the Zenor remains fixed.
B. The current through the series Resistance (Rs) changes.
C. The Zener resistance is constant.
D. The resistance offered by the Zener changes.
The answer is the option (b,d)
In forward biased mode, the zener diode act as a voltage regulator and used as an ordinary diode.
The zener diode in the reverse biased mode it offers constant voltage drop across the terminals as the unregulated voltage is applied. And during the regulation action of the zener diode, the current across the series resistance Rs is changed, therefore, resistance offered by the zener diode also changes. The current in the zener diode changes, but the voltage remains the same and constant.