What describes a form of induced voltage where air is the dielectric?

The option describing a form of induced voltage where air acts as the dielectric is capacitive coupling. In capacitive coupling, two conductors are separated by a dielectric material—in this case, air—allowing an electric field to form between them. This electric field can lead to the transfer of voltage from one conductor to another even when they are not in direct contact. This phenomenon is commonly observed in electrical systems where nearby conductors can influence each other through the air as the insulating medium.

In contrast, inductive coupling involves the transfer of energy through magnetic fields and is typically more relevant in scenarios where alternating currents create changing magnetic fields, inducing a voltage in nearby conductors. Ground potential rise pertains to the increase of voltage in the ground due to faults or lightning, and voltage drop refers to a reduction in voltage across a component in an electrical circuit due to resistance. These concepts do not involve the dielectric properties of air in the same way that capacitive coupling does.