Question

A transistor having $\alpha =$ $0.99$ is used in common base amplifier. If the load resistance is $0.45M\Omega$ and the dynamic resistance of the emitter junction is $50\Omega$, the voltage gain of the amplifier will be

• A. $7910$
• B. $8910$
• C. $9910$
• D. $6910$

Answer 1

The correct option is B $8910$

Given that:
Current gain $\alpha =0.99$
Load resistance, $R_L=0.45M\Omega =450000\Omega$
Internal resistance of diode $R_i=50\Omega$

Now resistance gain is, $\frac{R_L}{R_i}=\frac{450000}{50}=9000$

Hence, voltage gain = $\alpha \times \frac{R_L}{R_i}$

Voltage gain = $0.99\times 9000=8910$