When temperature increases, what happens to the earth’s resistivity?

When temperature increases, the resistivity of the earth generally decreases. This phenomenon occurs because, as temperature rises, the movement of charge carriers—such as electrons in the conduction band—becomes more efficient. In most materials, particularly semiconductors and conductors, higher temperatures allow for greater mobility of charge carriers, which lowers resistivity.

For the earth, which consists of various materials including soil and rock, an increase in temperature can lead to higher moisture evaporation and changes in the chemical composition of the materials present. These factors can enhance the conductivity of the soil as well, contributing to the reduction in resistivity.

In contrast, choices that suggest resistivity increases or remains unchanged do not align with the observed behavior of materials under temperature variations. The idea that resistivity would vary widely can be misleading without specific context, as changes tend to follow a more predictable pattern related to temperature increases. Thus, the relationship between temperature and resistivity is well established in materials science, confirming that resistivity decreases with rising temperatures.