The part of a transistor which is heavily doped to produce a large number of majority carriers is

In a transistor circuit, if emitter and collector connections are interchanged, then:

For a common emitter amplifier,the current gain is $50$. If the emitter current is $6.6 \ mA$,then the value of the base current is ........ (in $mA$)

The transfer characteristics [output voltage $(V_o)$ vs input voltage $(V_i)$] for a base-biased transistor in $CE$ configuration are shown in the figure. For using a transistor as a switch,it is used:

In a transistor amplifier, the base-emitter junction is forward-biased and the collector-base junction is reverse-biased. The current gain $(\beta)$ is defined as:

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: