An opamp question I can't make sense of

[circuit975]

Greetings to everyone,

I found all values in an opamp question, but I couldn't find the Vout output value. How do we do the formulation?
I mean, with which formula will we calculate vout?

 

[Diver300]

There is no feedback on the op-amp. The non-inverting input is higher than the inverting input so the output will be near the +ve supply, so about 12 V in this case.

 

[danadak]

Something wacky as well, The NI input is at 3V, the Inv at 2V, so
D is not 2V, its 1V. The inputs draw very small currents, on the
order of 80 nA. So drop across R's negligible.

Diver300 is correct as the differential input of 1V is amped by the Aol
of the OpAmp, so its close to its + rail because of no FDBK. The Aol
typically 200,000. The output V swing is ~ 1V off its supply rail, so
Vout ~ 13V.


Regards, Dana.