Question 515: Current Electricity

Question

In the following circuit, the current flowing through zener diode is

Accepted Answer

The voltage drop across $\mathrm{R}_2$ is
$$\mathrm{V}_2=\mathrm{V}_{\mathrm{z}}=8 \mathrm{~V}$$
The current through $\mathrm{R}_2$ is
$$\begin{aligned}
& \mathrm{I}_2=\frac{\mathrm{V}_2}{\mathrm{R}_2}=\frac{8}{1600}=5 	imes 10^{-3} \mathrm{~A} \
& \mathrm{I}_2=5 \mathrm{~mA}\quad	ext{... (i)}
\end{aligned}$$
The voltage drop across $\mathrm{R}_1$ is
$$\begin{aligned}
& V_1=20-V_2 \
& 20-8=12 V
\end{aligned}$$
The current through $R_1$ is
$$\begin{aligned}
& \mathrm{I}_1=\frac{\mathrm{V}_1}{\mathrm{R}_1}=\frac{12}{400}=3 	imes 10^{-2} \mathrm{~A}=30 	imes 10^{-3} \mathrm{~A} \
& \mathrm{I}_1=30 \mathrm{~mA}\quad	ext{... (ii)}
\end{aligned}$$
The current through the Zener diode is
$$\begin{aligned}
\mathrm{I}_{\mathrm{z}} & =\mathrm{I}_1-\mathrm{I}_2 \
& =(30-5) \mathrm{mA} \quad	ext{...[From (i) and (ii)]}\
& =25 \mathrm{~mA}
\end{aligned}$$

Answer

35 mA

Answer

25 mA

Answer

15 mA

Answer

5 mA

Current Electricity

In the following circuit, the current flowing through zener diode is

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