The opposite of conductivity, describing resistance to transfer of heat or electricity, is called what?

• A. Resistivity
• B. Conductivity
• C. Toughness
• D. Ductility

Answer: (A)

The key idea here is that energy transfer through a material is governed by two related properties: conductivity, which tells how easily heat or electric current can flow, and resistivity, which measures how strongly the material resists that flow. Resistivity is an intrinsic material property that opposes the movement of charges or heat. In electrical terms, the resistance you actually measure depends on both resistivity and the part’s geometry via R = resistivity × (length/area). A material with higher resistivity will have lower conductivity, and vice versa. For heat transfer, there’s a parallel concept called thermal resistivity, the reciprocal relationship to thermal conductivity, reinforcing that resistivity is the natural term for the resistance of transfer.

Toughness and ductility describe mechanical behavior under stress, not energy transfer, so they don’t fit here. Conductivity is the feature describing how easily transfer occurs, not the opposing property.