Is the voltage gain of a common-emitter ampilifier constant, irrespective of the magnitude of the input signal? Give reason.

Explanation

No, the voltage gain of a common-emitter amplifier is constant for a limited range of input signal `V_(i)`. Because, during the positive half cycle of input signal voltage, there is a support to the forward biasing of emitter-base circuit. Due to it, emitter current increases and hence collector current `(I_c)` increases. If `I_(C)` increases to such an extent that `V_(CE)` becomes less than `V_(BE)`, the transistor goes into a saturation state. Now the transistor does not work as an amplifier