For a transistor amplifier in common emitter configuration for load impedance of  1kΩ (hfe=50  and hoe=25μA/v ) the current gain is

For a transistor amplifier in common emitter configuration, current gain                                           Ai=−hfe1+hoeRLWhere hfe=50 and  hoe=25μA/v are hybrid parameters of a transistor.                                    ∴Ai=−501+25×10−6×1×103 =−501+25×10−3=−501+251000=−501+0.025 =−501.025=−48.78