What is the correct term for operation that alternates between load and no load conditions?

The correct term for operation that alternates between load and no load conditions is "Duty, Intermittent." This term accurately describes scenarios where a device or system operates for a period of time under a certain load, followed by off periods where there is no load. This type of duty cycle is common in various applications where devices are not required to run continuously, allowing them to conserve energy and reduce wear.

In contrast, "Continuous" duty refers to a scenario where the device operates under load without interruption, while "Short-Time" duty implies operation for a brief, defined period, typically with intervals of rest not specified. "Periodic" duty generally denotes operations that occur at regular intervals but still do not specifically capture the alternating load/no load pattern described. Thus, "Duty, Intermittent" is the most appropriate choice for this particular situation.