Question

most hammer drills will not hammer until pressure is ______.
○ released from the powder charge
○ reached in the hydraulic cylinder
○ detected at the trigger lock
○ applied to the drill bit

Explanation:

Hammer drills operate such that they start hammering when pressure is applied to the drill bit (this is related to the mechanism where the pressure on the bit triggers the hammering action; the other options don't align with the typical operation: powder charge is not relevant here, hydraulic cylinder pressure reaching isn't the trigger, and trigger lock detection is not the correct mechanism for hammer activation).

Answer:

D. applied to the drill bit