What is the main purpose of capacitors in electrical circuits?

The main purpose of capacitors in electrical circuits is to store electrical energy, which makes the first choice the correct understanding. Capacitors achieve this by accumulating charge on their plates when a voltage is applied, and they can release this stored energy when needed. This energy storage function is critical in various applications, such as smoothing out fluctuations in power supplies, filtering signals in electronic circuits, and providing timing elements in oscillators and timers.

While reducing non-performing power and improving circuit efficiency is certainly relevant to electrical systems, it is not the primary function of capacitors. Capacitors can help manage reactive power in AC circuits, which contributes to overall efficiency, but this is secondary to their fundamental role of energy storage. Ensuring voltage stability and protecting against surges are also important aspects of circuit design that may utilize capacitors, but these are not their main purposes. Overall, understanding capacitors as energy storage devices is key to grasping their function in circuits.