In the circuit shown, the input voltage to the op-amp ua741 is 1V and the output will be 5.7V, which switches the bottom left irfz44n mosfet on and the off voltage irfz44n mosfet off. So i would expect the voltage from the first voltage divider [0.8*12= 9.6- 0.7= 8.9 Volts] which is 8.9V to appear at the output (at the junction where sources of both mosfets and the 10kohm pull down resistor meet). However i get 2.13 volts with minute fluctuations. Why is this happening? How do i fix this. Threshold voltage of irfz44n is 4V.