Discussion Forum



1)

A Zener diode, having a breakdown voltage equal to 15 V  is used in a voltage regulator circuit shown in the figure. The current  through the diode is 

1102021899_j1.PNG


A) 10mA

B) 15 mA

C) 20mA

D) 5mA

Answer:

Option D

Explanation:

 1102021668_j2.PNG

 

For R=$1k \Omega$

$i_{1}=\frac{15}{1}mA=15 mA$

$R=250 \Omega$

$i_{250}=\frac{20-15}{250}=\frac{5}{250}=20mA$

$i_{Zener}=20-15=5mA$