When an $NPN$ transistor is used as an amplifier,which of the following occurs?

In a transistor,the value of $\alpha$ varies between $\frac{20}{21}$ and $\frac{100}{101}$. Then the value of $\beta$ varies between

In a study of a transistor as an amplifier,the ratio of collector current to emitter current is $0.98$. If the collector current is $3 \text{ mA}$,then the base current will be approximately:

An oscillator is nothing but an amplifier with

The current gain of a transistor is $0.98$. If the transistor is used in a common emitter arrangement, what would be the change in collector current corresponding to a change of $0.5 \,mA$ in the base current (in $\,mA$)?

In a common emitter amplifier,the input signal is applied across