Three circuit connections of a $PNP$ transistor are given below. Which of the following represents the Common-Emitter configuration?

In a common emitter amplifier,the output resistance is $5000 \Omega$ and the input resistance is $2000 \Omega$. If the peak value of input signal voltage is $100 mV$ and $\beta=50$,then the peak value of output voltage is

$A$ common emitter amplifier has a voltage gain of $50$,an input impedance of $100\; \Omega$,and an output impedance of $200\; \Omega$. The power gain of the amplifier is:

In a transistor,a change of $8.0\, mA$ in the emitter current produces a change of $7.8\, mA$ in the collector current. What change in the base current is necessary to produce the same change in the collector current? (in $\mu A$)

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $n-p-n$ transistor permits more current than a $p-n-p$ transistor.
Reason $R$: Electrons have greater mobility as a charge carrier.
Choose the correct answer from the options given below:

$A$ transistor is used in an amplifier circuit in common emitter mode. If the base current changes by $100 \,\mu A$, it brings a change of $10 \,mA$ in collector current. If the load resistance is $2 \,k \Omega$ and input resistance is $1 \,k \Omega$, the value of power gain is $x \times 10^{4}$. The value of $x$ is . . . . . . .