A zener diode, having breakdown voltage 15 V is used in a voltage regulator circuit as shown. The current through the zener diode is

Step-by-step solution

The voltage drop across 1 k is 15 V The current through it is I= 15 ~V 1 10^3 =15 10⁻³ ~A The voltage drop across 250 =20-15=5 ~V the current through it I= V R = 5 250 =20 10⁻³ ~A The current through zener diode is, I_z= (20 10⁻³ )- (15 10⁻³ )=5 ~mA