insulator

Examples of insulator in the following topics:

• Conductors and Insulators

  • Based on the ability to conduct current, materials are divided into conductors and insulators.
  • All materials can be categorized as either insulators or conductors based on a physical property known as resistivity.
  • While there is no perfect insulator with infinite resistivity, materials like glass, paper and Teflon have very high resistivity and can effectively serve as insulators in most instances.
  • Just as conductors are used to carry electrical current through wires, insulators are commonly used as coating for the wires.
  • This wire consists of a core of copper (a conductor) and a coating of polyethylene (an insulator).

• Dieletrics and their Breakdown

  • In all applications, they are selected for their ability to act as insulators.
  • By definition, an insulator is unable to conduct electricity.
  • Under certain conditions, however, a material that is an insulator can become a conductor.
  • Eventually, exposing any insulator to increasing voltage will result in the insulator becoming conductive.
  • This point (the minimum voltage for the insulator to become a conductor) is known as the breakdown voltage.

• Semiconductors

  • Semiconductors are materials that have properties in between those of normal conductors and insulators; they are often produced by doping.
  • Semiconductors are materials that have properties of both normal conductors and insulators.
  • Semiconductors and insulators are distinguished from metals by the population of electrons in each band.
  • Semiconductors and insulators are further distinguished by the relative band gap.
  • In insulators, it is large, making it difficult for electrons to flow through the conduction band.

• The bottom line

  • Future-proofing products involves working to insulate products and services from risk and uncertainty by eliminating waste in all phases of a product's life-cycle to: (1) avoid rises in raw material costs, (2) reduce the chances of bad publicity, and (3) prepare for coming changes in environmental legislation.

• Capacitors with Dielectrics

  • This interruption can come in the form of a vacuum (the absence of any matter) or a dielectric (an insulator).
  • Any insulator can be used as a dielectric, but the materials most commonly used are selected for their ability to resist ionization.
  • Eventually every material has a "dielectric breakdown point," at which the potential difference becomes too high for it to insulate, and it ionizes and permits the passage of current.

• Introduction to Building Better Buildings

  • Bougainvillea blossom under insulated skylights that cast a warm glow upon a profusion of grapevines and mango trees.
  • Layers of super-efficient insulation, heat-recovering ventilators and insulated windows help keep the building and its occupants warm all winter long.

• Safety Precautions in the Household

  • This wire is therefore safe to touch even if its insulation is missing.
  • Under ordinary circumstances, insulation on the live/hot and neutral wires prevents the case from being situated directly within the circuit, so that the earth/ground wire may seem like double protection.
  • The simplest problem is worn insulation on the live/hot wire that allows it to contact the case.
  • These appliances, including power tools with impact resistant plastic cases, have nonconducting cases and are called 'doubly insulated. ' Modern two-prong plugs can be inserted into the asymmetric standard outlet in only one way, ensuring the proper connection of live/hot and neutral wires.
  • Wire insulation colors vary by region.

• Heat Conservation and Dissipation

  • In certain climates, endothermic animals have some form of insulation, such as fur, fat, feathers, or some combination thereof.
  • Animals with thick fur or feathers create an insulating layer of air between their skin and internal organs.
  • The arctic fox uses its fluffy tail as extra insulation when it curls up to sleep in cold weather.

• Neuroglia of the Central Nervous System

  • They line up along the nerve fibers in the CNS and wrap their process tightly around the fibers producing an insulating covering called myelin sheath.
  • Oligodendrocytes form the electrical insulation around the axons of CNS nerve cells.

• Parallel-Plate Capacitor

  • The dielectric between the conductors is meant to act as an insulator, preventing charge from bridging the gap between the two plates.
  • In practice, dielectrics do not act as perfect insulators, and permit a small amount of leakage current to pass through them.