Question

A common base transistor amplifier has a current gain of $50$. If the load resistance is $4k$$\Omega$, and input resistance is $500$$\Omega$, the voltage gain of amplifier is

• A. $100$
• B. $200$
• C. $300$
• D. $400$

Answer 1

The correct option is D $400$

Given that:
$\beta$$=50$
$R_L=4k\Omega =4000\Omega$
$R_i=500\Omega$
Hence, resistance gain is
$\frac{R_L}{R_i}=\frac{4000}{500}=8$

For CB amplifier, voltage gain is,
Voltage gain = Current gain $\times$ Resistance gain
Voltage gain = $50$ $\times$ $8$
Voltage gain = $400$.