Q. Input offset voltage of operational amplifier?

When both inputs are tied to ground, i.e., both differential-mode and common-mode inputs are zero, the output should be zero. In practice there will be mismatches in amplifier components, and if there is a mismatch in an input stage, the effect will be amplified, leading to a significant output voltage. The input offset voltage VOS is the differential input voltage required to make the output zero, and is typically 1 mV. With some op amps, e.g., the 741, two voltage offset terminals are provided, and by connecting a potentiometer between them and taking the slider to the specified dc supply rail (or bus), as in Figure, the potentiometer can then be adjusted to zero the offset voltage.