No drilling shall be done within what distance from a misfired charge?

• A. 30 centimeters
• B. 60 centimeters
• C. 1 meter
• D. 2 meters

Answer: (B)

The main idea being tested is keeping a safe exclusion distance around a misfired charge to protect workers from delayed detonation and flying debris. Even when a charge fails to detonate as planned, the energy can still be released later or cause fragments to travel, so staying clear reduces the risk of injury. The standard minimum distance given is 60 centimeters because it provides a practical balance: far enough to lessen exposure to blast energy and projectiles, yet not so far as to be impractical for normal operations. A shorter distance, like 30 centimeters, would be too close and could still put people at risk; larger distances such as 1 meter or 2 meters are safer but exceed the required minimum in this rule. Therefore, 60 centimeters is the appropriate minimum in this context.