Question 88 of 209

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

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

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Answer: (B) $3.5 \text{mA}$

Current through $2K\Omega$ is
$i=\dfrac{10}{2000}=5mA$
Current through 4 $K\Omega$
${i}_{L}=i-{i}_{z}=\dfrac{6}{4000}=1.5mA$
$\Rightarrow {i}_{z}=i-1.5$
$∴{i}_{z}=5-1.5=3.5mA$