Question

A common emitter amplifier is designed with $NPN$ transistor $(\alpha =0.99)$.The input impedance is $1k\Omega$ and load is $10k\Omega$. The voltage gain will be

• A. $9.9$
• B. $99$
• C. $990$
• D. $9900$

Answer 1

The correct option is C $990$

Voltage gain $=\beta \times$ Resistance gain

$\beta =\frac{\alpha }{1-\alpha }=\frac{0.99}{(1-0.99)}=99$

Resistance gain $=\frac{10\times {10}^3}{{10}^3}=10$

$\Rightarrow$ Voltage gain $=99\times 10=990$