In a transistor amplifier,the voltage gain is

In which of the configurations of a transistor, the power gain is highest?

When a signal is applied to the input of a transistor,it is found that the output signal is phase-shifted by $180^{\circ}$. The transistor configuration is:

$A$ transistor is operated in $CE$ configuration at $V_{CC} = 2 \ V$ such that a change in base current from $100 \ \mu A$ to $200 \ \mu A$ produces a change in the collector current from $9 \ mA$ to $16.5 \ mA$. The value of current gain,$\beta$ is .........

In a common emitter transistor,the current gain is $80$. What is the change in collector current,when the change in base current is $250 \ \mu A$?

$A$ transistor having $\alpha = 0.99$ is used in a common base amplifier. If the load resistance is $4.5 \, k\Omega$ and the dynamic resistance of the emitter junction is $50 \, \Omega$,the voltage gain of the amplifier will be: