What value of current-limiting resistor would appropriately bias a 1-watt, 10-volt Zener diode in a 20-V power supply?

What value of current-limiting resistor would appropriately bias a 1-watt, 10-volt Zener diode in a 20-V power supply?

• A. 150 ohms
• B. 200 ohms
• C. 250 ohms
• D. 300 ohms

Answer: (B)

To determine the appropriate value of the current-limiting resistor for a Zener diode, we start by analyzing the Zener diode's operating conditions. In this case, the Zener diode has a breakdown voltage of 10 volts, and it is designed to operate at a power rating of 1 watt. When connected to a power supply of 20 volts, the current-limiting resistor is necessary to ensure that the current through the Zener diode does not exceed its maximum ratings, especially when the diode is in the breakdown region. First, we need to calculate the maximum current that the Zener diode can handle safely. This is derived from its power rating: \[ P = V \times I\, \Rightarrow\, I = \frac{P}{V} \] Substituting the power rating (1 watt) and the Zener voltage (10 volts): \[ I = \frac{1\, \text{W}}{10\, \text{V}} = 0.1\, \text{A} = 100\, \text{mA} \] Next, we calculate the voltage that must be dropped across the resistor. With the Zener diode maintaining 10 volts, the voltage drop

To determine the appropriate value of the current-limiting resistor for a Zener diode, we start by analyzing the Zener diode's operating conditions. In this case, the Zener diode has a breakdown voltage of 10 volts, and it is designed to operate at a power rating of 1 watt.

When connected to a power supply of 20 volts, the current-limiting resistor is necessary to ensure that the current through the Zener diode does not exceed its maximum ratings, especially when the diode is in the breakdown region.

First, we need to calculate the maximum current that the Zener diode can handle safely. This is derived from its power rating:

[

P = V \times I, \Rightarrow, I = \frac{P}{V}

]

Substituting the power rating (1 watt) and the Zener voltage (10 volts):

[

I = \frac{1, \text{W}}{10, \text{V}} = 0.1, \text{A} = 100, \text{mA}

]

Next, we calculate the voltage that must be dropped across the resistor. With the Zener diode maintaining 10 volts, the voltage drop