I'm unable to come to terms with something I think is a paradoxical situation relating to the virtual ground of an Operational Amplifier.Please pardon me if this is a really stupid question.
When the 'Negative Feedback' in an Op-Amp (Ideal) makes the difference between its input terminals equal to 'Zero'. Shouldn't the output become zero too because the Op-Amp is fundamentally a Differential Amplifier and according to the equation:
Vo = (Open loop gain)*(Differential voltage b/w the inputs)
The Explanations I've come up with so far are:-
1) The Op-Amp Output is indeed zero and it is the External Circuitry (consisting of resistors Rf and Rin) that create the voltage, which adds up to the Op-Amp output voltage (in this case Zero) at point B to create the actual output of the system.
2) The virtual ground is not perfect and there exists a very very small differential voltage at the input which gets multiplied by the vary high gain and produces the output.
I'm fundamentally unable to understand how the actual definition of Op-Amp behavior is consistent with the virtual ground phenomenon without making the output zero. Please Help!