Question

In the given circuit the current through Zener Diode is close to

• A. $0.0mA$
• B. $6.7mA$
• C. $6.0mA$
• D. $4.0mA$

Answer 1

Answer: (A)

If we consider break down in zener diode, then potential across $R_2$ will be $10V$ and $R_1$ will be $2V.$
So current in $R_2$ will be $i_2=\frac{10}{1500}=\frac{2}{300}A$
and current in $R_1$ will be $i_3=\frac{2}{500}A$
$\Rightarrow i_1<i_3,$ which is not possible
$\Rightarrow$ Potential difference across zener diode does not reach to break down voltage. So no current will flow through reverse biased zener diode.