A p-n junction in series with a resistance of `5 kOmega` is connected across a 50 V DC source . If the forward bias resistance of the junction is `50 Omega` , the forward bias current is

Options

A. 1 mA
B. 2 mA
C. 20 mA
D. 9.9 mA

Answer

To find the forward bias current through the p-n junction in series with a resistance, we can follow these steps:

### Step 1: Identify the total resistance in the circuit
The total resistance \( R_{total} \) in the circuit is the sum of the forward bias resistance of the diode \( R_d \) and the series resistance \( R_s \):
\[ R_{total} = R_s + R_d \]
Given:
- \( R_s = 5 \, k\Omega = 5000 \, \Omega \)
- \( R_d = 50 \, \Omega \)

Calculating \( R_{total} \):
\[ R_{total} = 5000 \, \Omega + 50 \, \Omega = 5050 \, \Omega \]

### Step 2: Apply Ohm's Law to find the current
Using Ohm's Law, the current \( I \) through the circuit can be calculated using the formula:
\[ I = \frac{V}{R_{total}} \]
Where \( V \) is the voltage of the DC source. Given:
- \( V = 50 \, V \)

Substituting the values:
\[ I = \frac{50 \, V}{5050 \, \Omega} \]

### Step 3: Calculate the current
Now, let's calculate the current:
\[ I = \frac{50}{5050} \approx 0.0099 \, A \]

### Step 4: Convert the current to milliamperes
Since \( 1 \, A = 1000 \, mA \):
\[ I \approx 0.0099 \, A \times 1000 \, mA/A \approx 9.9 \, mA \]

### Final Answer
The forward bias current is approximately \( 9.9 \, mA \).

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