Which of the following statements about the Op-Amp differential amplifiers is INCORRECT?
1
The output of the Op-Amp must be zero when the voltages applied at its terminal are different to each other.
2
An Op-Amp operating in differential mode can readily act as a subtractor amplifier
3
These devices are used as motor or servo controllers.
4
The basic circuit can be modified in many ways resulting in various circuit designs including Wheatstone bridge differential amplifier.