Re: Transistor circuit
First of all, to make this circuit working properly you will need to swap transistors: Q1 should be PNP and Q2 NPN ..
Also, you don't need R4 resistor in this circuit ..
With these changes implemented, the o/p will be H (almost +12V) as both transistors are "ON" .. Q2 saturated by the AND-gate (output of U1 =H as V2 and V3 =H), Q1 saturated by Q2 ..
If output of U1 is L (V2 or V3 is L) then the o/p will be floating, as Q1 is OFF .. and there is nothing else to define the stage of this point ..
Regards,
IanP