Which fault condition exists when one or more line conductors contact the earth potential?

The correct answer is grounded. This term specifically refers to a fault condition where one or more conductors make contact with the earth's surface or an object that is at earth potential. When this happens, the electrical current can flow directly to the ground, leading to potential hazards such as equipment damage or safety risks to personnel.

Ground faults can occur in various ways, such as insulation failure or accidental contact with conductive materials. Identifying a ground fault is crucial for implementing safety measures, as these types of faults can lead to electric shock or fires if not properly addressed.

The other terms are related to different electrical conditions: cross refers to the unintended contact between two live conductors, typically causing a short circuit; short signifies a low-resistance connection between two points in a circuit, usually resulting in excessive current flow; and open indicates a break in the circuit where current cannot flow. While each of these fault conditions is important in understanding electrical systems, they do not specifically encapsulate the scenario where a line conductor is in contact with earth potential as effectively as the term grounded does.