Which term describes the measure of a material's opposition to the flow of electric current—the property that increases with poorer conductivity?

• A. Electrical resistance
• B. Conductivity
• C. Electrical resistivity
• D. Dielectric strength

Answer: (C)

The property in question is resistivity. It is the intrinsic measure of how strongly a material opposes the flow of electric charges, independent of its size or shape. As a material becomes a poorer conductor, its resistivity increases. This is captured by the relation R = ρL/A, which shows how resistance of a sample depends on its length and cross-sectional area, while resistivity ρ is a constant property of the material itself. Conductivity, the reciprocal of resistivity, would decrease as resistivity increases, so it does not fit the description. Dielectric strength concerns how much electric field a material can withstand before breakdown, not regular current flow.