If the current amplification factor for a transistor connected in common emitter configuration is 100 and input resistance is `200 Omega`, then the power gain is (Assume output resistance is `0.8 kOmega`)

Options

A. `4xx10^(4)`
B. `5xx10^(3)`
C. `7xx10^(3)`
D. `45xx10^(4)`

Answer

To solve the problem, we need to calculate the power gain of a transistor in a common emitter configuration using the given values. The power gain (Pg) can be expressed in terms of the current gain (β) and the voltage gain (Av). Let's go through the steps:

### Step 1: Identify the given values
- Current amplification factor (β) = 100
- Input resistance (R_BE) = 200 Ω
- Output resistance (R_L) = 0.8 kΩ = 800 Ω

### Step 2: Calculate the current gain (β)
The current gain (β) is already given as 100.

### Step 3: Calculate the voltage gain (A_V)
The voltage gain (A_V) in a common emitter configuration can be calculated using the formula:
\[ A_V = \frac{\beta \cdot R_L}{R_{BE}} \]
Substituting the values:
\[ A_V = \frac{100 \cdot 800}{200} \]
\[ A_V = \frac{80000}{200} = 400 \]

### Step 4: Calculate the power gain (P_g)
The power gain (P_g) can be calculated using the formula:
\[ P_g = A_V \cdot \beta \]
Substituting the values:
\[ P_g = 400 \cdot 100 = 40000 \]
This can be expressed in scientific notation:
\[ P_g = 4 \times 10^4 \]

### Conclusion
The power gain of the transistor is \(4 \times 10^4\).

### Final Answer
The correct option is Option 1: \(4 \times 10^4\).