In the above analysis we saw that the two input terminals are forced to the same voltage even though no current flows through either terminal This situation is called a virtual short circuit and occurs because the op-amp output forces the inverting terminal voltage to precisely track the voltage supplied to the non-inverting terminal The situation is analogous to two magnets on either side of a window If one magnet is raised the other magnet will precisely track it even though there is no physical connection between them The concept of the virtual short is extreamely useful in analyzing operational amplifier circuits