Question 101 of 209

The value of the resistor, ${R}_{S}$, needed in the DC voltage regulator circuit shown here, equals:

A$\dfrac{\left({V}_{i}+{V}_{L}\right)}{\left(n+1\right){I}_{L}}$B$\dfrac{\left({V}_{i}-{V}_{L}\right)}{n{I}_{L}}$C$\dfrac{\left({V}_{i}+{V}_{L}\right)}{n{I}_{L}}$D$\dfrac{\left({V}_{i}-{V}_{L}\right)}{\left(n+1\right){I}_{L}}$

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Answer: (D) $\dfrac{\left({V}_{i}-{V}_{L}\right)}{\left(n+1\right){I}_{L}}$

Across zener diode ${V}_{L}=constant$

$∵{V}_{i}={V}_{L}+\left(n+1\right){I}_{L}{R}_{S}$

$\Rightarrow {V}_{i}-{V}_{L}=\left(n+1\right){I}_{L}{R}_{S}$

$\Rightarrow {R}_{S}=\dfrac{{V}_{i}-{V}_{L}}{\left(n+1\right){I}_{L}}$

JEE Main Physics practice question on Semiconductors (Diodes), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.