In a P-N junction , for a 0.2 V change in the forward bias voltage, the corresponding change in current is 20 mA. The dynamic resistance of the P-N junction is

Options

A. `30 Omega`
B. `10 Omega`
C. `40 Omega`
D. `20 Omega`

Answer

To find the dynamic resistance of a P-N junction, we can use the formula for dynamic resistance (Rd):

\[ R_d = \frac{\Delta V}{\Delta I} \]

Where:
- \( \Delta V \) is the change in voltage
- \( \Delta I \) is the change in current

### Step-by-Step Solution:

1. **Identify the given values**:
- Change in forward bias voltage, \( \Delta V = 0.2 \, \text{V} \)
- Change in current, \( \Delta I = 20 \, \text{mA} = 20 \times 10^{-3} \, \text{A} = 2 \times 10^{-2} \, \text{A} \)

2. **Substitute the values into the formula**:
\[ R_d = \frac{0.2 \, \text{V}}{2 \times 10^{-2} \, \text{A}} \]

3. **Calculate the dynamic resistance**:
\[ R_d = \frac{0.2}{0.02} = 10 \, \Omega \]

4. **Final answer**:
The dynamic resistance of the P-N junction is \( 10 \, \Omega \).