Which term best describes operation involving both load and rest conditions in a set pattern?

The term that best describes operation involving both load and rest conditions in a set pattern is "Duty, Intermittent." This classification refers specifically to machinery or equipment that operates for a defined duration with periods of inactivity or rest, effectively cycling between active and inactive states. This pattern of operation is significant in various applications, as it allows for cooling and prevents overheating, ensuring the longevity and reliability of the equipment.

Intermittent duty is commonly found in devices such as fans, pumps, and other machinery where there are clear on-off cycles that are predictable and repeatable. This structured use helps in managing energy consumption and reducing wear and tear, which is crucial for achieving operational efficiency.

In contrast, the other terms describe different types of duty cycles that do not fit the description of having both load and rest conditions in a specific pattern. continuous duty refers to operation without interruptions, varying duty implies fluctuating loads without a set pattern, and short-time duty indicates a brief, defined operation period but not necessarily incorporating rest periods or a specific cycle pattern.