National Council Of Examiners For Engineering And Surveying (NCEES) Fundamentals Of Engineering (FE) Electrical And Computer Practice Exam

A capacitor is the circuit element that stores electrical energy in an electric field. It consists of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied across the plates, an electric field is created, causing positive charge to accumulate on one plate and negative charge on the other. This process allows the capacitor to store energy in the form of an electric field between the plates. The energy stored in a capacitor can be calculated using the formula \( E = \frac{1}{2} CV^2 \), where \( E \) is the stored energy, \( C \) is the capacitance, and \( V \) is the voltage across the plates. This characteristic makes capacitors essential components in various applications, including filtering, energy storage, and smoothing voltage fluctuations in power supply circuits. On the other hand, resistors dissipate energy as heat, inductors store energy in a magnetic field, and transformers transfer electrical energy between circuits through electromagnetic induction. While inductors also store energy, it is specifically in the form of a magnetic field, not an electric field like in capacitors. Therefore, the correct choice is the capacitor, as it distinctly defines the storage of electrical energy in an electric field.