In a triode valve the amplification factor is 20 and mutual conductance is 10–3 mho . The plate resistance is

Options

A. `2xx10^(3) Omega`
B. `4xx10^(3)Omega`
C. `2xx10^(4) Omega`
D. `2xx10^(4)Omega`

Answer

To find the plate resistance (rp) of a triode valve given the amplification factor (μ) and mutual conductance (gm), we can use the following relationship:

\[ r_p = \frac{\mu}{g_m} \]

### Step-by-Step Solution:

1. **Identify the given values:**
- Amplification factor (μ) = 20
- Mutual conductance (gm) = \( 10^{-3} \) mho

2. **Substitute the values into the formula:**
\[ r_p = \frac{μ}{g_m} = \frac{20}{10^{-3}} \]

3. **Calculate the plate resistance:**
- To divide by \( 10^{-3} \), we can multiply by \( 10^{3} \):
\[ r_p = 20 \times 10^{3} = 20000 \, \text{ohms} \]

4. **Convert to kilohms if necessary:**
\[ r_p = 20 \, \text{kΩ} \]

### Final Answer:
The plate resistance (rp) is 20 kΩ.