What is one notable feature of the Aluminum Conductor Steel-Reinforced (ACSR) cable regarding thermal expansion?

The notable feature of Aluminum Conductor Steel-Reinforced (ACSR) cable regarding thermal expansion is that it tends to stretch when heated. This characteristic is significant because, like many materials, ACSR cables expand as they are subjected to increased temperatures. The aluminum core, which has a higher coeficient of thermal expansion compared to steel, contributes prominently to this behavior.

When the cable heats up, the thermal energy causes the atoms in the material to move more vigorously, leading to an increase in length. This expansion must be considered in engineering and design, particularly in overhead power lines, to prevent issues such as sagging or mechanical failure. Therefore, understanding this thermal expansion is crucial for ensuring safety and reliability in utility applications involving ACSR cables.

The other options do not accurately describe the behavior of ACSR in relation to thermal expansion, as they imply stability or rigidity that is not characteristic of the material's response to heat.