The phase difference between input and output voltage of a $CE$ circuit is.....$^o$

In an $n-p-n$ transistor,

The power gain and voltage gain of a transistor connected in common emitter configuration are $1800$ and $60$ respectively. If the change in the emitter current is $0.62 \text{ mA}$, then the change in the collector current is: (in $\text{ mA}$)

$A$ transistor is operated in common emitter configuration at $V_C = 2 \, V$ such that a change in the base current from $100 \, \mu A$ to $300 \, \mu A$ produces a change in the collector current from $10 \, mA$ to $20 \, mA$. The current gain is

$A$ transistor is used as a common emitter amplifier with a load resistance $2 \ k\Omega$. The input resistance is $150 \ \Omega$. The base current is changed by $20 \ \mu A$,which results in a change in collector current by $1.5 \ mA$. The voltage gain of the amplifier is

In a transistor amplifier,the voltage gain is