For a common-emitter transistor amplifier, the current gain is $60$. If the emitter current is $6.6 \,mA$, then its base current is (in $\,mA$)

In a $CE$-transistor feedback oscillator circuit,the phase difference between input and output signal is

For a transistor,the parameter $\beta = 99$. The value of the parameter $\alpha$ is

If $\alpha = 0.98$ and the current through the emitter $i_e = 20 \, mA$,the value of $\beta$ is

In a transistor, if $\frac{I_C}{I_E} = \alpha$ and $\frac{I_C}{I_B} = \beta$. If $\alpha$ varies between $\frac{20}{21}$ and $\frac{100}{101}$, then the value of $\beta$ lies between:

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.