Which electrical malfunction occurs when the contacts of a switch or relay are welded closed?

When the contacts of a switch or relay are welded closed, it creates a situation where the circuit remains permanently closed, leading to a continuous flow of current. This condition is referred to as a shorted control. A shorted control can result in various operational issues, such as equipment running continuously or overheating, since the device governed by the switch or relay cannot turn off as intended. This can also pose significant safety hazards and could potentially damage the electrical circuit involved.

The other options address different types of electrical faults. A ground fault involves current flowing through an unintended path to ground, while a direct short refers to a situation where there is little or no resistance in a circuit, typically bypassing the intended load. An intermittent fault describes issues that occur sporadically, rather than being a constant issue like a shorted control. Therefore, the situation where contacts are welded closed is most accurately classified as a shorted control.