In a transistor, comparing the doping of emitter, base, and collector, the part which is heavily doped and that which is lightly doped are respectively:

For the given bipolar junction transistor,find the approximate value of $I_B$,if $V_{CC} = 9 \ V$,$V_{BB} = 1.5 \ V$,$R_C = 13 \ k\Omega$,$R_E = 17 \ k\Omega$,and $\beta = 100$. (Assume the transistor is in active mode and $V_{BE} = 0.7 \ V$)

In a common-emitter transistor,the current gain $\beta$ is $49$. If there is a change of $5.0 \ \mu A$ in the base current,what will be the change in the collector current and the emitter current?

In a $p-n-p$ transistor,

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: