Question

In a given circuit diagram, a 5 V zener diode along with a series resistance is connected across a 50 V power supply. The minimum value of the resistance required, if the maximum zener current is 90 mA will be _____ Ω.

Answer 1

Answer is 500

Voltage across R_L = 5V

⇒ i₂ = \(\cfrac5{R_L}\)

Also voltage across R = 50 – 5 = 45 volt

Current in zener diode is maximum when R_L→∞