Question 28: Semiconductors and Logic Gates

Question

A zener diode with 5 V zener voltage is used to regulate an unregulated dc voltage input of 25 V . For a $400 \Omega$ resistor connected in series, the zener current is found to be 4 times load current. The load current $\left(I_L\right)$ and load resistance $\left(R_L\right)$ are :

Accepted Answer

From the circuit diagram,
$$\begin{aligned}
& 5 \mathrm{i}=\frac{20}{400}=\frac{1}{20} \mathrm{~A} \
& 	herefore \mathrm{i}=\frac{1}{100} \mathrm{~A}=10 \mathrm{~mA}=	ext { Load current }
\end{aligned}$$
Also, $\mathrm{V}_{\mathrm{L}}=5 \mathrm{~V}$
$$	herefore \mathrm{R}_{\mathrm{L}}=\frac{5}{10 	imes 10^{-3}} \Omega=500 \Omega$$

Answer

$\mathrm{I}_{\mathrm{L}}=0.02 \mathrm{~mA} ; \mathrm{R}_{\mathrm{L}}=250 \Omega$

Answer

$\mathrm{I}_{\mathrm{L}}=10 \mathrm{~A} ; \mathrm{R}_{\mathrm{L}}=0.5 \Omega$

Answer

$\mathrm{I}_{\mathrm{L}}=10 \mathrm{~mA} ; \mathrm{R}_{\mathrm{L}}=500 \Omega$

Answer

$\mathrm{I}_{\mathrm{L}}=20 \mathrm{~mA} ; \mathrm{R}_{\mathrm{L}}=250 \Omega$

Semiconductors and Logic Gates

A zener diode with 5 V zener voltage is used to regulate an unregulated dc voltage input of 25 V . For a 400 \Omega resistor connected in series, the zener current is found to be 4 times load current. The load current \left(I_L\right) and load resistance \left(R_L\right) are :

Choose the correct answer: