Final answer:
The No. 18 gauge galvanized iron wire has a diameter of approximately 1.024 millimeters. The mass and time for galvanizing iron sheets involve calculating the volume of zinc needed and applying Faraday's laws for the electrolytic process.
Step-by-step explanation:
The thickness of galvanized iron wire can vary, but when speaking of wire gauge, particularly No. 18 gauge wire, the diameter is approximately 1.024 millimeters or 0.0403 inches. The gauge system, specifically the American Wire Gauge (AWG), is used to standardize wire diameters. For instance, the diameter of a 14-gauge copper wire is about 1.628 millimeters.
When addressing the example regarding galvanizing the top of an iron sheet, we need to consider the area to be galvanized and the thickness of the zinc coating. Given that the sheet dimensions are 3.00 meters by 5.50 meters and the zinc coating thickness is 0.100 millimeters, we calculate the volume of zinc required by multiplying the area of the sheet by the thickness of the zinc layer. Using the density of zinc (7.140 g/cm³), we can then calculate the mass of zinc needed for galvanization. To determine the time required for galvanization using an electrolytic process with a current flow of 25.5 Amperes, Faraday's laws of electrolysis would be applied.