What will the output of a differential amplifier be when both inputs receive identical in-phase signals?

When both inputs of a differential amplifier receive identical in-phase signals, the output will be zero. This is because a differential amplifier is designed to amplify the difference between its two inputs. When the inputs are the same and in-phase, there is no difference to amplify, resulting in a net output of zero.

Differential amplifiers operate on the principle of subtraction, meaning they take the voltage of one input and subtract it from the voltage of the other input. In this case, since both inputs are identical, the subtraction yields a result of zero. This characteristic is fundamental to the function of differential amplifiers, especially in applications such as instrumentation and signal processing, where noise rejection is important.

In situations where the inputs are not identical, the output would correspond to the amplification of the difference between the two signals. However, with identical signals, the differential amplifier effectively cancels out both signals, leading to no output.