Dielectric strength refers to the ability of insulation to withstand:

Dielectric strength is a crucial property of insulating materials, defined as the maximum electric field that a dielectric can withstand without experiencing breakdown or failure. This means that dielectric strength is concerned with the ability of the insulation to resist electrical breakdown when subjected to a high potential difference, or voltage. When the electric field exceeds this strength, the insulating material can become conductive, leading to a failure in the insulation's ability to perform its function.

The context of dielectric strength is particularly relevant in applications where electrical components are exposed to high voltages. Insulating materials must maintain their integrity to prevent current leakage, arcing, or short circuits.

High temperatures, total electrical resistance, and mechanical stress may affect materials in other ways, but they do not directly relate to the concept of dielectric strength, which specifically addresses electrical insulation's response to voltage. Therefore, the most accurate definition of dielectric strength pertains to its capacity to withstand a potential difference without breaking down, confirming the correctness of that choice.