Which component's strength can be measured by its dielectric strength?

Dielectric strength is a key characteristic of capacitors, which refers to the maximum electric field that a material can withstand without breaking down and becoming conductive. This property is crucial for capacitors because they store electrical energy in an electric field created between two conductive plates separated by an insulating material, known as a dielectric.

When the voltage applied across the capacitor exceeds its dielectric strength, the insulation can fail, leading to a short circuit and potential damage to the capacitor and surrounding components. Therefore, measuring dielectric strength helps engineers ensure that a capacitor can operate safely within its intended voltage range without risking electrical breakdown.

The other components listed do not primarily rely on dielectric strength for their function. Inductors are based on magnetic fields, resistors depend on resistive materials, and transformers work through mutual induction, none of which feature dielectric properties at the level of significance found in capacitors.