What determines the resistivity of a material?

• A. The material's temperature and physical shape
• B. The material's composition and temperature
• C. The material's color and texture
• D. The material's thickness and length

Answer: (B)

The resistivity of a material is fundamentally determined by its composition and temperature. Composition refers to the specific elements or compounds that make up the material and how they are structured at the atomic or molecular level. Different materials have varying abilities to conduct electricity; for example, metals generally have low resistivity, while insulators like rubber have high resistivity.

Temperature also plays a critical role in resistivity. For most conductive materials, an increase in temperature results in an increase in resistivity. This is because higher temperatures cause atoms to vibrate more, which impedes the flow of electrons, thereby increasing the material's resistance to electrical flow.

In contrast, other factors such as color, texture, thickness, and length can influence how we perceive a material or its application in specific contexts but do not fundamentally determine the intrinsic resistivity of the material itself.