Current actually flows into or out of a virtual ground.

More Questions from Operational Amplifiers

• An open feedback resistor in an inverting or noninverting op-amp circuit can cause severe clipping of the output signal.
• An S-R flip-flop is an example of a bistable multivibrator circuit.
• The frequency of a crystal is dependent on how much voltage is applied to activate it.
• If the two inputs to a differential amplifier are exactly the same, then the output is the signal multiplied by two.
• If an input signal is applied to the inverting input of an op-amp with the noninverting input grounded, the output signal would be opposite in polarity with the input.
• A monostable multivibrator must be triggered.
• The difference between the upper and lower trigger points is called the Schmitt trigger.
• The inverting input is pin 2.
• A voltage-follower op-amp has the output connected directly to the inverting input.
• This circuit is a bandpass filter.

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