An amplifier is represented by the circuit shown in Fig. Here `r_(i)` is the input resistance of the amplifier and the voltage `V_(i)` is appearing across it. This voltage is amplified by a factor `A_(V)` and appears across the load as voltage` V_(0)`
An external voltage V_(s) is applied at the input terminals of the amplifier via series resistance R_(S). What will be the apparent gain `A_(V)(=V_(0)//V_(s))` of the ampilifier in terms of `A_(V), R_(S) and r_(i).`