Question

In a Zener diode regulated power supply, unregulated DC input of $10V$ is applied. If the resistance$\left(R_s\right)$ connected in series with a Zener diode is $200\Omega$ and the Zener voltage $V_z=5V$, the current across the resistance $R_s$ is:

• A. $15mA$
• B. $10mA$
• C. $20mA$
• D. $5mA$
• E. $25mA$

Answer 1

The correct option is E $25mA$

Voltage drop across $R_s$ is
$(10-5)=5V$
$\therefore I=\frac{V}{R_s}=\frac{5}{200}=0.025$A
$=25mA$.