Question

In a transistor amplifier, AC current gain is $64$ , the load resistance is $5400\Omega$ and the input resistance of the transistor is $540\Omega$. The voltage gain is

• A. 540
• B. 600
• C. 640
• D. 6400

Hint:

Voltage gain is dimensionless and scales current gain by the ratio of output to input resistance.

Answer 1

The Correct Option is C

Step 1: Concept
Voltage gain ($A_v$) is the product of current gain ($\beta$) and resistance gain ($R_L / R_i$).

Step 2: Meaning
$A_v = \beta \times \frac{R_{out}}{R_{in}}$.

Step 3: Analysis
Given $\beta = 64$, $R_L = 5400\Omega$, $R_i = 540\Omega$.
$A_v = 64 \times \frac{5400}{540} = 64 \times 10$.

Step 4: Conclusion
$A_v = 640$. Final Answer: (C)