Junction Transistor

In a transistor circuit, the collector current is changed by $89 \mathrm{mA}$, if the emitter current is changed to $9.0 \mathrm{mA}$. The value of current amplification factor, $\beta$ is

Consider an amplifier circuit wherein a transistor is used in common emitter mode. The change in collector current and base current respectively are $4 \mathrm{mA}$ and $20 \mu$ A when a signal of $40 \mathrm{mV}$ is added to the base-emitter voltage. If the load resistance is $10 \mathrm{k\Omega }$, then power gain in the circuit is