81st Academy Practice Exam 2026 – The Comprehensive All-in-One Guide for Success!

When an electric field acts on a non-conductive material, heat can be produced inside the material because the molecules polarize and continually reorient in response to the alternating field. The imperfect alignment and lag between the field and the dipoles cause dielectric losses, converting electrical energy into heat. This specific heating mechanism is called dielectric heating.

This differs from arc heating, which requires an electric arc and a conductive path, and from thermal conduction or conductive heating, which involve heat transfer due to temperature differences or contact, not direct conversion of electrical energy within a dielectric. Dielectric heating is why insulators in AC fields or in dielectric heating processes (like some industrial heating or microwave interactions) get warm.