dielectric

dy-ih-LEK-trik /ˌdaɪɪˈlɛktrɪk/
nounadjectiveC2GREGATEAP Physics
technicalacademic

An electrical insulator that can be polarized by an applied electric field, storing electrostatic energy.

Unlike simple non-conductors, dielectrics actively hold shifted atomic charges when exposed to electric fields.

The story behind the word. Coined by William Whewell at the request of Michael Faraday from Greek 'dia' (through) + 'electric'. It describes materials through which electric field force lines can act without current flowing.

Word relationships

  • insulator: An insulator prevents current flow; a dielectric is an insulator evaluated specifically for its electric field storage ability.
  • conductor: Conductors allow charge to flow freely, whereas dielectrics hold charges fixed in place while polarizing.

Commonly confused with

  • electrolyte: An electrolyte conducts current via dissolved ions, whereas a dielectric is an insulator that polarizes under voltage.

Word family

  • dielectrically (adverb): In a manner pertaining to dielectrics.

Collocations

  • dielectric constant
  • dielectric breakdown
  • dielectric strength
  • dielectric material

Example sentences

  • "Ceramic materials serve as efficient dielectric layers between metal plates in modern capacitors." Capacitor technology documentation
  • "Exceeding the maximum dielectric strength causes electrical breakdown and permanent sparks through the material." Insulator breakdown research

Memory hook

DIA = THROUGH electric field lines pass WITHOUT current. An insulating material that stores electric fields.

When not to use

Do not use as a synonym for simple electrical insulation when polarization properties are irrelevant.

Fun facts

  • Pure water has a very high dielectric constant (about 80), making it great at shielding electric charges at atomic scales.
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