Which of these is a unipolar transistor?

In an $NPN$ transistor,$10^{10}$ electrons enter the emitter in $10^{-6} \ s$ and $2\%$ of the electrons recombine with holes in the base. The current gains $\alpha$ and $\beta$ are respectively:

The current gain of a transistor is $0.98$. If the transistor is used in a common emitter arrangement, what would be the change in collector current corresponding to a change of $0.5 \,mA$ in the base current (in $\,mA$)?

The current gain for a transistor working as a common base amplifier is $0.96$. If the emitter current is $7.2 \,mA$, then the base current is (in $\,mA$)

In the common emitter mode of a transistor, when the collector-emitter voltage is changed by $0.4 \, V$, the collector current changes by $0.04 \, mA$. The output resistance is

In a common base circuit of a transistor,the amplification factor is $0.95.$ The base current when the emitter current is $2\,mA,$ is ....$mA$