What is the purpose of an operational amplifier (op-amp)?

The purpose of an operational amplifier (op-amp) is to perform mathematical operations on signals, which encompasses a wide range of functions such as addition, subtraction, integration, differentiation, and many more. Op-amps are fundamental components in analog signal processing and are widely used in various applications where signal manipulation is required.

In operational amplifier circuits, you can find configurations that allow these mathematical operations to be carried out on the input signals. For instance, in a summing amplifier arrangement, multiple input voltages can be combined to produce a single output voltage that is proportional to the sum of the inputs, thus effectively performing an addition operation. Similarly, other configurations can be designed to achieve different mathematical tasks.

The other choices do not comprehensively describe the primary role of an op-amp. While op-amps can measure voltage as part of their operation, that is not their main purpose. Voltage regulation is typically achieved using different types of circuits, not specifically by op-amps. Additionally, while filtering can be accomplished with op-amps in specific configurations, stating that they act only as a filtering device is too restrictive and neglects their broader utility in mathematical signal processing.