A transistor does not act as an amplifier. It is used as a
component in an amplifier circuit.
View page
A PNP transistor has no advantage or disadvantage over an NPN
transistor in its ability as an amplifier. Rather, the
current-handling capacities of the transistor determine if it's
usable as an amplifier.
View page
That depends on both the input signal and the type of amplifier
the transistor is used in.
View page
A transistor
View page
it doesn't have to be. depends on design of amplifier using
transistor.