What phenomenon is described by the term 'thermal shock'?

The term 'thermal shock' refers specifically to the phenomenon that occurs when a material is subjected to rapid changes in temperature. This rapid exposure can cause stress within the material, leading to potential cracks or failures due to the differential expansion or contraction rates of various sections of the material.

For instance, if a hot object is suddenly cooled (like a glass dish placed into cold water), the outer layer may contract faster than the inner layer, producing tension and possibly resulting in a break. Understanding thermal shock is essential in industries where materials are frequently subjected to temperature fluctuations, as it can help in designing components to withstand such conditions without failing.

Other options describe different phenomena: gradual extension under stress relates to creep, while sudden breakage hints at brittle fracture under load. Static electricity buildup does not involve temperature changes and is unrelated to thermal shock. Thus, these options do not accurately represent the concept of thermal shock as it pertains to rapid temperature changes.