Power Gain of CE amplifier circuit is given by

Options

A. Voltage gain × current gain
B. Voltage gain/Current gain
C. Current gain/Voltage gain
D. (Voltage gain)^2 × current gain

Answer

To determine the power gain of a Common Emitter (CE) amplifier circuit, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Common Emitter Configuration:**
- The Common Emitter (CE) configuration is a type of transistor amplifier where the emitter terminal is common to both the input and output circuits. This configuration can be used with both NPN and PNP transistors.

2. **Define Power Gain:**
- Power Gain (denoted as \( P_G \)) is defined as the ratio of the output power (\( P_{out} \)) to the input power (\( P_{in} \)).
\[ P_G = \frac{P_{out}}{P_{in}} \]

3. **Relate Power to Voltage and Current:**
- Power can be expressed in terms of voltage and current. The power in an electrical circuit is given by:
\[ P = V \times I \]
- Therefore, we can express the output power and input power as:
\[ P_{out} = V_{out} \times I_{out} \]
\[ P_{in} = V_{in} \times I_{in} \]

4. **Express Power Gain in Terms of Voltage and Current Gain:**
- The voltage gain (\( A_V \)) is defined as the ratio of output voltage to input voltage:
\[ A_V = \frac{V_{out}}{V_{in}} \]
- The current gain (\( A_I \)) is defined as the ratio of output current to input current:
\[ A_I = \frac{I_{out}}{I_{in}} \]

5. **Combine the Gains to Find Power Gain:**
- By substituting the expressions for power into the power gain formula, we get:
\[ P_G = \frac{V_{out} \times I_{out}}{V_{in} \times I_{in}} = A_V \times A_I \]
- Thus, the power gain of a Common Emitter amplifier can be expressed as:
\[ P_G = A_V \times A_I \]

6. **Conclusion:**
- The formula for the power gain of a Common Emitter amplifier circuit is given by the product of its voltage gain and current gain.