What occurs when terminal ground switches at each end of an energized and deenergized transmission line are closed?

When terminal ground switches at each end of an energized and deenergized transmission line are closed, circulating current will flow through the deenergized line and earth due to the difference in potential between the energized line and the grounded deenergized line. This situation creates a pathway for current to circulate through earth, as the two lines have different electrical states.

In this circumstance, the energized line remains at a higher potential compared to the deenergized line, leading to a potential difference that drives current to flow through the grounded path. This current flow can lead to various operational concerns such as temperature increases in the line and potential disturbances in ground fault protection systems.

The other options do not accurately describe the consequences of closing the ground switches in this context. If no current flows, the system wouldn't respond as expected, and grounding electricity or isolating power are not the appropriate outcomes when the conditions of the terminal ground switches are activated in this manner.