Question

In the given circuit, the current through zener diode is :

• A. $5.5mA$
• B. $6.7mA$
• C. $2.5mA$
• D. $3.3mA$

Answer 1

Answer: (D)

Voltage across $R_1$ is given by
$V_{R_1}=V-V_z=15-10=5V$. Resistance $R_1=500\Omega$

Therefore, current through $R_1$ is given by
$I_{R_1}=\frac{5V}{500\Omega }=0.01A$.
Now current through $R_2$ is given by
$I_{R_2}=\frac{10V}{1500\Omega }=0.067A$.
Therefore, the current through Zener diode will be
$0.01-0.0067=0.0033A=3.3mA$