The region in the output voltage versus input voltage graph where a transistor can be used as an amplifier is

For a $CE$ transistor amplifier,the audio signal voltage across the collector resistance of $2.0\,k\Omega$ is $2.0\,V$. Suppose the current amplification factor of the transistor is $100$. What should be the value of $R_B$ (in $k\Omega$) in series with $V_{BB}$ supply of $2.0\,V$ if the $dc$ base current has to be $10$ times the signal current?

For a transistor in $CE$ mode to be used as an amplifier,it must be operated in:

The dc common emitter current gain of an $n-p-n$ transistor is $50$. The potential difference applied across the collector and emitter of a transistor used in $CE$ configuration is $V_{CE} = 2 \ V$. If the collector resistance $R_{C} = 4 \ k\Omega$,the base current $(I_{B})$ and the collector current $(I_{C})$ are:

In a $NPN$ transistor,$10^8$ electrons enter the emitter in $10^{-8} \ s$. If $1\%$ of electrons are lost in the base,the fraction of current that enters the collector and the current amplification factor $\beta$ are respectively:

$A$ transistor having a $\beta$ equal to $80$ has a change in base current of $250 \mu A$. What is the change in collector current?