What does corona refer to in electrical terminology?

In electrical terminology, corona refers to the tendency of electrons to leave a conductor, particularly under high voltage conditions. When the electric field around a conductor becomes sufficiently strong, it can cause air molecules surrounding the conductor to ionize. This process allows electrons to escape into the surrounding air, creating a phenomenon known as corona discharge. This occurrence is often visible as a bluish glow around the conductor and can result in energy loss and degradation of the conductor or insulation over time.

The other options do not accurately describe corona. The flow of electrons through a capacitor specifically relates to electric charge storage and does not involve the ionization of air. Shedding of electrical insulation refers to physical damage or wear to insulating materials rather than electron movement and ionization. Electrical arcing is a more severe event involving a sustained discharge between conductors, which is distinct from the more subtle phenomenon of corona discharge.