In a common base amplifier,the phase difference between the input signal voltage and the output voltage is

$A$ 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 . . . . . . .

Which two of the following statements are true for a transistor?
$(1)$ The base,emitter,and collector regions of a transistor have the same size and doping concentration.
$(2)$ The base region is thin and lightly doped.
$(3)$ The emitter-base junction is forward-biased,and the base-collector junction is reverse-biased.
$(4)$ Both the emitter-base junction and the base-collector junction are forward-biased.

In a $CE$ transistor amplifier,the audio signal voltage across the collector resistance of $2 \, k\Omega$ is $2 \, V$. If the base resistance is $1 \, k\Omega$ and the current amplification of the transistor is $100$,the input signal voltage is

When a transistor is used as a $CB$ transistor amplifier,the current gain is $0.8$. If the change in base current is $6 \ mA$,then the change in collector current is ....... $mA$.

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: