In which section of a transistor is the doping concentration highest to produce a large number of majority charge carriers?

Assertion: $A$ transistor amplifier in common emitter configuration has a low input impedance.
Reason: The base-to-emitter region is forward-biased.

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 $\,mA$)?

In an $n-p-n$ common emitter $(CE)$ transistor,the collector current changes from $5\,mA$ to $16\,mA$ for a change in base current from $100\,\mu A$ to $200\,\mu A$,respectively. The current gain of the transistor is:

In the case of a common emitter transistor amplifier,the ratio of collector current to emitter current is $0.96$. Then,the current gain $(\beta)$ of the amplifier is:

The part of a transistor which is heavily doped to produce a large number of majority carriers is