For a transistor circuit in common emitter configuration, the voltage gain is 100. If the input voltage is 20 m V, then the output voltage is

Options

A. 400 mV
B. 1 V
C. 2 V
D. 0.5 V

Explanation

To solve the problem step by step, we need to use the formula for voltage gain in a transistor circuit. The voltage gain (A_V) is defined as the ratio of the output voltage (V_O) to the input voltage (V_I).

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Voltage Gain (A_V) = 100
- Input Voltage (V_I) = 20 mV = 20 x 10^(-3) V

2. **Use the Formula for Voltage Gain:**
The formula for voltage gain is:
\[ A_V = \frac{V_O}{V_I} \]
Rearranging this formula to find the output voltage (V_O):
\[ V_O = A_V \times V_I \]

3. **Substitute the Known Values:**
Now, substitute the values of A_V and V_I into the equation:
\[ V_O = 100 \times (20 \times 10^{-3} \text{ V}) \]

4. **Calculate the Output Voltage:**
Now perform the multiplication:
\[ V_O = 100 \times 20 \times 10^{-3} = 2000 \times 10^{-3} \text{ V} \]
\[ V_O = 2 \text{ V} \]

5. **Conclusion:**
The output voltage (V_O) is 2 V.

### Final Answer:
The output voltage is **2 V**.