NEIEP Mechanics Practice Exam

When drilling a jack hole, which characteristics must it possess?

1. Must be large enough, deep, and round

2. Must be straight, plumb, and to the proper depth

3. Must be straight, wide, and shallow

4. Must be horizontal, deep, and straight

The correct answer is: Must be straight, plumb, and to the proper depth

The characteristics of a jack hole are critical for ensuring it functions as intended. For a jack hole to be effective, it must be straight, meaning that it maintains a uniform path throughout its length, which is essential for the proper alignment and operation of the equipment that will be used in concert with the hole. Being plumb indicates that the hole must be vertical, which ensures that the drilling is precise and the jacking tools or equipment can operate effectively without any misalignment. Correct depth is also crucial; the hole must reach a specific depth to ensure that any load placed upon it is appropriately supported, thereby providing the necessary stability and safety for the operation. Other characteristics suggested in the other options do not prioritize the critical aspects of alignment and depth that are essential for the drilling process. For example, size and shape may vary in different applications, but the straightness, plumbness, and appropriate depth directly affect the functionality and safety of the hole.