For box openings having any dimension less than 8 in (200 mm), the minimum length of conductor measured from the box opening in the wall to the end of the conductor is ________.

• A. 1 in. (25 mm)
• B. 3 in. (75 mm)
• C. 6 in. (150 mm)
• D. 8 in. (200 mm)

Answer: (B)

When a box opening is smaller than 8 inches, you need a short tail of conductor outside the wall to give you room to work, make terminations, and accommodate the connector without forcing wires back into the box. This free length helps you grip, strip, and position the conductors safely and efficiently during installation, while also allowing a bit of slack so tightening clamps or connectors doesn’t pull the wire back in. For this scenario, the minimum exposed length from the box opening to the end of the conductor is 3 inches.