Question

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

• A. 10 $mA$
• B. 15 $mA$
• C. 20 $mA$
• D. 5 $mA$

Answer 1

The correct option is D 5 $mA$

Consider the circuit


For 1 k$\Omega$
$i_1=\frac{15}{1}=15mA$
For 250 $\Omega$
$i^{}=\frac{20-15}{250}=\frac{5}{250}=\frac{20}{1000}=20mA$
$\therefore i_2=20-15=5mA$