Elevator Mechanic Practice Exam

Using a rotary or auger bit is the most suitable choice for drilling a jack hole in sandy conditions because these types of drill rigs are specifically designed for drilling in granular soils. A rotary drill uses a rotating drill bit to cut through the material, while an auger bit has a helical shape that helps in removing the drilled material efficiently.

In sandy conditions, where the soil lacks cohesion, using a drill that can effectively manage and remove the loose material is critical. The rotary action allows for the stabilization of the hole, reducing the risk of collapse, and the continuous removal of sand helps maintain the integrity of the drilling operation.

Other types of bits, such as a combination bit, impact bit, or sonic bit, may not be as effective in this specific scenario due to their design features and intended applications. Their efficiency in handling sandy conditions would not be optimal compared to the rotary or auger bit, making the latter the preferred choice.