Question

In the circuit (Fig.), the current through Zener diode is (in $\text{mA}$) :

Answer 1

Using Ohms law,
$I_{R_2}=\frac{V_z}{1500}=\frac{1}{150}\text{A}\downarrow$
$I_{R_1}=\frac{15-V_z}{R_1}=\frac{1}{100}\text{A}\downarrow$
From kirchoff's current law
$\Rightarrow I_z=I_{R_1}-I_{R_2}$
$=\frac{1}{300}\text{A}=3.33\text{mA}$