In a Germanium diode, the forward current increases from 100mA to 200 mA, when forward voltage changes from 5V to 10V. The forward resistance of the diode is

Options

A. `20 Omega `
B. `50 Omega `
C. `100 Omega `
D. `500 Omega `

Answer

To find the forward resistance of the Germanium diode, we can use the formula derived from Ohm's law, which states that resistance (R) is equal to the change in voltage (ΔV) divided by the change in current (ΔI).

### Step-by-Step Solution:

1. **Identify the Initial and Final Values:**
- Initial current (I1) = 100 mA = 100 × 10^(-3) A = 0.1 A
- Final current (I2) = 200 mA = 200 × 10^(-3) A = 0.2 A
- Initial voltage (V1) = 5 V
- Final voltage (V2) = 10 V

2. **Calculate the Change in Voltage (ΔV):**
\[ ΔV = V2 - V1 = 10 V - 5 V = 5 V \]

3. **Calculate the Change in Current (ΔI):**
\[ ΔI = I2 - I1 = 200 mA - 100 mA = 100 mA = 100 × 10^{-3} A = 0.1 A \]

4. **Calculate the Forward Resistance (Rf):**
Using the formula for resistance:
\[ R_f = \frac{ΔV}{ΔI} \]
Substitute the values:
\[ R_f = \frac{5 V}{0.1 A} = 50 \, \Omega \]

5. **Conclusion:**
The forward resistance of the diode is 50 ohms.

### Final Answer:
The forward resistance of the diode is **50 Ω**.