Which combination lists the factors that influence soil resistivity?

Study for the BICSI OSP Design Test. Prepare using multiple choice questions, with hints and explanations to enhance understanding. Succeed in your exam journey!

Soil resistivity is governed by how easily ions can move through the soil’s pore water and how the soil’s physical makeup affects those pathways. The amount of water in the soil directly controls conductivity: more moisture means more ions in the liquid phase and more continuous paths for current. Temperature matters because ions move faster at higher temperatures, which lowers resistivity. The salt content, or salinity, raises the concentration of ions in the pore water, further increasing conductivity and reducing resistivity. Finally, the soil’s composition—its texture, mineral content, and organic matter—determines pore size, connectivity, and how much water the soil can hold, all of which influence how readily current travels through the soil.

Among the options, the set that includes soil composition, moisture, salt content, and temperature captures these core influences on resistivity. The other choices mix in factors that don’t directly set the soil’s ability to conduct electricity: wind speed isn’t a persistent determinant of bulk soil resistivity, root density isn’t a fundamental property of the soil’s conductivity, and soil color is an indicator rather than a controlling factor.