$A$ transistor is connected in a common emitter configuration with $R_o = 4 \text{ k}\Omega$,$R_i = 1 \text{ k}\Omega$,$I_C = 1 \text{ mA}$,and $I_b = 20 \text{ }\mu\text{A}$. The voltage gain is:

In an $n-p-n$ transistor circuit,the collector current is $10 \text{ mA}$. If $95\%$ of the electrons emitted reach the collector,then the base current is nearly: (in $mA$)

To use a transistor as an amplifier,which of the following conditions must be satisfied?

For a transistor in the active region:
$(a)$ Base,emitter,and collector regions should have similar size and doping concentrations.
$(b)$ The base region must be very thin and lightly doped.
$(c)$ The emitter-base junction is forward-biased and the base-collector junction is reverse-biased.
$(d)$ Both the emitter-base junction and the base-collector junction are forward-biased.
Which one of the following pairs of statements is correct?

When $n-p-n$ junction transistor is used as an amplifier in common emitter mode,

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