IGCSE Physics Practice Exam 2026 – Complete Study Resource

When a material is subjected to a force that exceeds its elastic limit, it undergoes a change in its structural integrity. The elastic limit is the maximum amount of stress that a material can withstand while still being able to return to its original shape once the force is removed. When this limit is surpassed, the material experiences plastic deformation, which means it will not return to its original shape after the force is removed.

This irreversible change occurs because the internal molecular structure of the material has been altered under the excessive force. The bonds within the material are rearranged, resulting in a permanent deformation or, in some cases, leading to breaking if the force is sufficiently high. Understanding this behavior is critical in fields like engineering and materials science for ensuring that structures and components are designed to operate within safe stress limits.