What is the primary role of capacitors in electric circuits?

The primary role of capacitors in electric circuits is to store electrical energy temporarily. Capacitors are components that can accumulate and hold charge, creating an electric field between their plates. When connected to a power source, they can absorb energy in the form of electrical charge, which can then be released back into the circuit when needed.

This ability to store and release energy gives capacitors several important functions in electronic circuits, including filtering, smoothing out voltage fluctuations, and maintaining power during short interruptions. For example, in power supply circuits, capacitors help to smooth out the output voltage by absorbing surges and releasing energy when there are dips in power, thus ensuring a steady voltage supply.

While some of the other choices involve aspects related to electronics (such as converting power or measuring electrical parameters), they do not capture the essential and primary purpose of capacitors, which is centered around energy storage.