What happens if one power line has a voltage around it in relation to an adjacent line?

When one power line has a voltage present, it creates an electric field around itself. This electric field can influence nearby conductors, such as an adjacent power line, leading to the phenomenon known as electromagnetic induction. In this process, the alternating electric field from the energized line induces a voltage in the adjacent line. This induced voltage occurs without physical contact between the two lines, demonstrating the principle of induction where a changing electric field can produce an electric effect in nearby conductors.

The reason other answers are not applicable is that simply becoming neutral, dissipation of voltage, or losing grounding do not accurately represent the behavior of a nearby line when exposed to the electric field from an energized line. The interaction is based on induction principles rather than grounding status or direct electrical connection.