[[File:b2MAN_Fig109.png|thumb|350px|An Op-Amp circuit with two voltage probes.]]
[[File:b2MAN_Fig110.png|thumb|left|600px|A Cartesian graph showing the input and output voltages of the Op-Amp circuit.]]
==Using Probes as Observables==
[[File:b2MAN_Fig110b2MAN_Fig111.png|thumb|left|600px300px|A Cartesian graph showing table displaying the input and output voltages of the Op-Amp circuit.]]