The current gain for a transistor used in common - emitter configuration is 98. If the load resistance be `1 M Omega` and the internal resistance be `600Omega` , what is the voltage gain ?

Options

A. 90
B. 95
C. 100
D. none

Answer

To find the voltage gain (Av) of a transistor in a common-emitter configuration, we can use the formula:

\[ A_v = \beta \cdot \frac{R_L}{R_I} \]

Where:
- \( \beta \) is the current gain of the transistor,
- \( R_L \) is the load resistance,
- \( R_I \) is the internal resistance.

**Step 1: Identify the given values.**
- Current gain (\( \beta \)) = 98
- Load resistance (\( R_L \)) = 1 MΩ = \( 1 \times 10^6 \, \Omega \)
- Internal resistance (\( R_I \)) = 600 Ω

**Step 2: Substitute the values into the formula.**
\[ A_v = 98 \cdot \frac{1 \times 10^6}{600} \]

**Step 3: Calculate the fraction first.**
\[ \frac{1 \times 10^6}{600} = \frac{1000000}{600} \approx 1666.67 \]

**Step 4: Multiply by the current gain.**
\[ A_v = 98 \cdot 1666.67 \approx 163333.33 \]

**Step 5: Express the result in scientific notation.**
\[ A_v \approx 1.633333 \times 10^5 \]

**Step 6: Round the answer to a suitable number of significant figures.**
\[ A_v \approx 16.33 \times 10^4 \]

Thus, the voltage gain \( A_v \) is approximately \( 16.33 \times 10^4 \).