[amp_mcq option1=”28.4 mA” option2=”24.2 mA” option3=”34.4 mA” option4=”68.4 mA E. None of the above” correct=”option1″]
The correct answer is: A. 28.4 mA
The zener current is the current that flows through the zener diode when it is in regulation. It is calculated by the following formula:
$I_Z = \frac{V_S – V_Z}{R_S}$
where:
- $I_Z$ is the zener current
- $V_S$ is the source voltage
- $V_Z$ is the zener voltage
- $R_S$ is the series resistance
In this case, we have:
- $V_S = 20\text{ V}$
- $V_Z = 12\text{ V}$
- $R_S = 330\Omega$
Therefore, the zener current is:
$I_Z = \frac{20\text{ V} – 12\text{ V}}{330\Omega} = 28.4\text{ mA}$
Option B is incorrect because it is the zener current when the source voltage is 12 V. Option C is incorrect because it is the zener current when the series resistance is 12 V. Option D is incorrect because it is the zener current when the source voltage is 20 V and the series resistance is 12 V. Option E is incorrect because it is not a valid option.