a
\(\Delta i _{ B }=100 \,\mu A \quad \beta=\frac{\Delta i _{ C }}{\Delta i _{ B }}\)

\(\Delta i _{ c }=10 \,mA\)

power \(=\beta^{2} \times \frac{R_{0}}{R_{i n}}\)

Power \(=\left(\frac{10}{0.1}\right)^{2} \times \frac{2}{1}\)

Power \(=100 \times 100 \times 2\)

Gain \(=2 \times 10^{4}\)