Question

Figure shows a DC voltage regulator circuit, with a Zener diode of breakdown voltage \(= 6~\text V\). If the unregulated input voltage varies between \(10~\text V~ \text{to}~ 16~\text V\) , then what is the maximum Zener current ?




R, =4kQ

• A. $2.5\text{mA}$
• B. $7.5\text{mA}$
• C. $3.5\text{mA}$
• D. $1.5\text{mA}$

Answer 1

The correct option is C $3.5\text{mA}$

Current in the load resistance is,
$I_1=\frac{6}{4\times {10}^3}=1.5\times {10}^{-3}A=1.5\text{mA}$

For $V=16\text{Volt},$

$I=\frac{(16-6)}{2\times {10}^3}=5\text{mA}$

$\therefore I_m=I-I_1=5-1.5=3.5\text{mA}$

Hence, $\left(D\right)$ is the correct answer.