For a common emitter amplifier,the current gain is $50$. If the emitter current is $6.6 \ mA$,then the value of the current gain when it acts as a common base amplifier is:

In a common emitter amplifier circuit using an $n-p-n$ transistor,the phase difference between the input and the output voltages will be.....$^o$

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:

$Assertion$ : In common base configuration, the current gain of the transistor is less than unity.
$Reason$ : The collector terminal is reverse biased for amplification.

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

In a silicon transistor,a change of $7.89 \, mA$ 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 an equivalent change in the collector current (in $mA$)?