If the forward voltage in a semiconductor diode is changed from 0.5V to 0.7 V, then the forward current changes by 1.0 mA. The forward resistance of diode junction will be

Options

A. `100 Omega`
B. `120 Omega`
C. `200 Omega`
D. `240 Omega`

Explanation

To find the forward resistance of the diode junction, we can use Ohm's Law, which relates voltage (V), current (I), and resistance (R) as follows:

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

Where:
- \( R \) is the resistance,
- \( \Delta V \) is the change in voltage,
- \( \Delta I \) is the change in current.

### Step 1: Calculate the change in voltage (\( \Delta V \))
The forward voltage changes from 0.5 V to 0.7 V. Therefore, the change in voltage is:

\[ \Delta V = V_{\text{final}} - V_{\text{initial}} \]
\[ \Delta V = 0.7 \, \text{V} - 0.5 \, \text{V} = 0.2 \, \text{V} \]

### Step 2: Convert the change in current (\( \Delta I \))
The change in current is given as 1.0 mA. We need to convert this to amperes:

\[ \Delta I = 1.0 \, \text{mA} = 1.0 \times 10^{-3} \, \text{A} \]

### Step 3: Substitute values into the resistance formula
Now, we can substitute the values of \( \Delta V \) and \( \Delta I \) into the formula for resistance:

\[ R = \frac{\Delta V}{\Delta I} \]
\[ R = \frac{0.2 \, \text{V}}{1.0 \times 10^{-3} \, \text{A}} \]

### Step 4: Calculate the resistance
Now, calculate the resistance:

\[ R = \frac{0.2}{1.0 \times 10^{-3}} = 200 \, \Omega \]

### Conclusion
The forward resistance of the diode junction is \( 200 \, \Omega \).

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