Question 1:
difficultA zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the zener diode is:
Voltage across 250 ohm resistor= 5 volt
Current through 250 ohm resistor= 5/250 = 20 mA
Current through 1000 ohm resistor = 15/1000 = 15mA
Current through Zener Diode = 20 mA -15 mA = 5 mA