question_answer

Is the voltage gain of a CE amplifier constant irrespective of the magnitude of the input signal? Give reason.

Answer:

                    No. The voltage is constant for a limited range of input signal \[{{V}_{i}}\]. During the positive half-cycle, base current \[{{I}_{B}}\] increases which increases collector current \[{{I}_{C}}\]. If the increase in \[{{I}_{C}}\] is so large that \[{{V}_{CE}}\] becomes less than \[{{V}_{BE}}\], the transistor goes into saturation state. Therefore, when \[\beta {{I}_{B}}>{{I}_{C}}\] the transistor does not work as an amplifier.