Question

The virtual ground of an op-amp means:
A. Terminal is grounded directly
B. Terminal is not physically grounded but terminal voltage is zero due to the other terminal being connected to the ground due to op-amp properties.
C. Both A and B
D. None of these.

Answer 1

Hint: A virtual ground is defined as a node of a circuit which is at a steady reference potential. It is a concept that is made for simple explanation and measurement purposes as the voltage is around zero. These all may help you to solve this question.

Complete step by step answer:
Real ground is if a terminal is connected physically to the ground or the earth. By the way virtual ground is a concept which is used in Op-Amps in which a node is considered to have the potential that is the same as that of the ground terminal. It is not actually physically connected to the ground. Voltage is a differential quantity, which appears to be in between two points. So in short we can see from here that the virtual ground of an op-amp is not physically grounded but the terminal voltage is made zero. Therefore the correct answer for this question is option B.

Note:
In order to deal only with the voltage or an electrical potential of a single point, the second point should be connected to a reference point, usually ground. Generally the power supply terminals serve as the constant grounds where the internal points of a compound power source are accessible, they can also be used as real grounds. When there are no accessible source internal points, the external circuit points having constant voltage with respect to the source terminals can be used as artificial virtual grounds. Such a point should be having steady potential, which does not vary when a load is getting attached.