Question 206: Semiconductors and Logic Gates

Question

A $$8 \mathrm{~V}$$ Zener diode along with a series resistance $$\mathrm{R}$$ is connected across a $$20 \mathrm{~V}$$ supply (as shown in the figure). If the maximum Zener current is $$25 \mathrm{~mA}$$, then the minimum value of R will be _______ $$\Omega$$.

Accepted Answer

Applying voltage rule in loop ABCD.
$$
\begin{aligned}
\mathrm{E}-\mathrm{IR}-\mathrm{V}_{\mathrm{Z}} & =0 \\
20-\mathrm{IR}-8 & =0 \\
2.5 	imes 10^{-3} 	imes \mathrm{R} & =12
\end{aligned}
$$
$\mathrm{R}=\frac{12}{25 	imes 10^{-3}}=480 \Omega$

Semiconductors and Logic Gates

A $8 \mathrm{~V} Zener diode along with a series resistance \mathrm{R} is connected across a 20 \mathrm{~V} supply (as shown in the figure). If the maximum Zener current is 25 \mathrm{~mA}, then the minimum value of R will be _______ \Omega$.

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