For a common base transistor,the current gain is $\alpha = 0.98$. To produce a change of $2 \ mA$ in the emitter current,the change in the base current must be ......... $mA$.

For a transistor in the active region:
$(a)$ Base,emitter,and collector regions should have similar size and doping concentrations.
$(b)$ The base region must be very thin and lightly doped.
$(c)$ The emitter-base junction is forward-biased and the base-collector junction is reverse-biased.
$(d)$ Both the emitter-base junction and the base-collector junction are forward-biased.
Which one of the following pairs of statements is correct?

For a common emitter amplifier,the voltage gain is $50$,the input resistance is $200 \ \Omega$,and the output resistance is $400 \ \Omega$. The power gain of the amplifier will be:

In a transistor amplifier,$\beta = 62$,$R_L = 5000\, \Omega$,and the internal resistance of the transistor is $R_i = 500\, \Omega$. The voltage amplification of the amplifier will be:

In an $NPN$ transistor, the collector current is $28 \text{ mA}$. If $80\%$ of the electrons emitted by the emitter reach the collector, what is the base current in $\text{mA}$ (in $\text{ mA}$)?

In a common emitter amplifier circuit using an $n-p-n$ transistor,the phase difference between the input and the output voltages will be.....$^o$