Plate electrodes shall be at least ___ inches thick when made of nonferrous metal.

• A. 0.06 millimeters
• B. 0.186 inches
• C. 1.52 inches
• D. 0.06 inches

Answer: (D)

The idea is to know the minimum thickness required for nonferrous plate electrodes so they stay mechanically strong and make reliable electrical contact. The standard sets that minimum at 0.06 inches, which is about 1.5 mm. That thickness provides enough rigidity to resist bending or damage during handling and use, without adding unnecessary bulk or cost. The other options aren’t correct for the minimum: 0.06 millimeters is far too thin to meet the requirement, 1.52 inches is far thicker than needed and impractical, and 0.186 inches, while thicker than the minimum, isn’t the specified minimum value.