An op-amp with no feedback (open loop) used as a comparator gives an output that:

Saturates at one supply rail or the other

A Schmitt trigger differs from a plain comparator because it has:

Two switching thresholds (hysteresis)

Almost 0 V by negative feedback

Minus the sum of the inputs scaled by the feedback ratio

Each feeds the virtual earth, which is held near 0 V

Amplifies the difference of two inputs and rejects common-mode signals

Buffer stages giving very high input resistance

The ratio of the feedback resistors

13questions. Pick an answer and you'll see why right away.

An ideal operational amplifier has an input resistance that is:
An op-amp with no feedback (open loop) used as a comparator gives an output that:
A Schmitt trigger differs from a plain comparator because it has:
The voltage gain of an inverting amplifier is:
The voltage gain of a non-inverting amplifier is:
The virtual earth in an inverting amplifier is the inverting input being held at:
A voltage follower (buffer) has a voltage gain of:
In a summing amplifier with equal input resistors, the output is:
Why do the inputs of a summing amplifier not interact with each other?
A difference amplifier is useful because it:
An instrumentation amplifier improves on a plain difference amplifier mainly by adding:
Negative feedback makes an op-amp amplifier's gain depend on:
An instrumentation amplifier is especially suited to amplifying the signal from a: