The input characteristics of a transistor in $CE$ mode is the graph obtained by plotting

For a transistor to act as a switch,it must be operated in

In a transistor,the base is made very thin and is lightly doped with an impurity because:

For a transistor,$\beta = 100$. The value of $\alpha$ is

When a transistor is used as an amplifier in common emitter configuration,which of the following statements are correct?
$(1)$ The base-emitter junction is forward-biased.
$(2)$ The base-emitter junction is reverse-biased.
$(3)$ The input signal is connected in series with the biasing voltage to the base-emitter junction.
$(4)$ The input signal is connected in series with the biasing voltage to the base-collector junction.

In an $NPN$ transistor circuit,the collector current is $10 \,mA$. If $90\%$ of the electrons emitted reach the collector,the emitter current $(i_E)$ and base current $(i_B)$ are given by