Realise circuit for hFe measurement
I realised this circuit and got superimposed signal S = DC + "e_g" = 1 + sin(2*PI*10^4*t) by connecting grounds of two voltage sources together and their positive terminals to ground and positive of the circuit. 

I also put capacitor in parallel with transistor as shown, for varying capacitance: 1uF, 100uF, 1000uF. The observed result of that is decrease in collector current from 0.37mA to 0.322mA.

Capacitor value | Collector current | Base current | Beta = Ic/Ib


-,0.37mA, 1.2uA, 308
1uF, 0.35mA, 1.1uA, 318
100uF, 0.322mA, 1.1uA, 293
1000uF, 0.322mA, 1.1uA, 293


All currents measured with DC current function of multimeter. Resistance is 430 kOhm (bbutton to base) and 100 Ohm (Vcc to collector), transistor is 2N3904 with hFe300 in datasheet.