Question

For the circuit shown in the figure :

• A. Current through Zener diode is $4mA$
• B. Current through Zener diode is $9mA$
• C. The output voltage is $60V$
• D. The output voltage is $40V$

Answer 1

Answer: (B)

Here, $I=\frac{70}{5000}=\text{1.4}\times 10^{-2}A$
$V_{\text{Z}}=120-70$
$=50V$ (output voltage Across diode)
$I_L=\frac{50}{10000}=5\times 10^{-3}A=\text{0.5}\times 10^{-2}A$
$\Rightarrow I_{\text{Z}}=\left(\text{1.4}-\text{0.5}\right)\times 10^{-2}A$
$=9\times 10^{-3}A$
$=9mA$