Question 89 of 209

The figure represents a voltage regulator circuit using a Zener diode. The breakdown voltage of the Zener diode is $6V$ and the load resistance is, ${R}_{L}=4k\Omega$ . The series resistance of the circuit is ${R}_{i}=1k\Omega$ . If the battery voltage ${V}_{B}$ varies from $8V$ to $16V$ , what are the minimum and maximum values of the current through Zener diode?

A$0.5mA;6mA$B$1mA;8.5mA$C$0.5mA;8.5mA$D$1.5mA;8.5mA$

Show answer and solution▾

Answer: (C) $0.5mA;8.5mA$

For ${V}_{0}=8V$

$8V-1000{i}_{0}=6V$
${i}_{0}=2mA$
${i}_{0}-{i}_{1}=\dfrac{6}{4000}=1.5mA$
${i}_{1}=0.5mA$
For ${V}_{0}=16V$

$16V-1000{i}_{0}=6V$
${i}_{0}=10mA$
${i}_{0}-{i}_{2}=\dfrac{6}{4000}=1.5mA$
${i}_{2}=8.5mA$