Question

The inverting input inverting of the voltage shunt feedback resistor is a commonly named as

(a) Terminal ground

(b) Virtual ground

(c) Virtual input

(d) Resistive input

This question was posed to me in an interview for internship.

My question comes from Voltage Shunt Feedback Amplifier in section Operational Amplifier Characteristics of Linear Integrated Circuits

Answer 1

Right option is (b) Virtual ground

To make it clear: Ideally, the difference between input voltages is zero. Therefore, the voltage at the inverting terminal is approximately equal to that of non-inverting terminal. In other words, the inverting terminal voltage is approximately at ground potential and it is said to be virtual ground.