Ad
related to: which elements are good insulators
Search results
Results From The WOW.Com Content Network
String insulators can be made for any practical transmission voltage by adding insulator elements to the string. [14] Also, if one of the insulator units in the string breaks, it can be replaced without discarding the entire string. Each unit is constructed of a ceramic or glass disc with a metal cap and pin cemented to opposite sides.
This is a list of insulation materials used around the world.. Typical R-values are given for various materials and structures as approximations based on the average of available figures and are sorted by lowest value.
Boron, being a metalloid, is a thermal and electrical insulator at room temperature, but a good conductor of heat and electricity at high temperatures. [8] Unlike boron, the metals in the group are good conductors under normal conditions.
A compound semiconductor is a semiconductor compound composed of chemical elements of at least two different species. These semiconductors form for example in periodic table groups 13–15 (old groups III–V), for example of elements from the Boron group (old group III, boron, aluminium, gallium, indium) and from group 15 (old group V, nitrogen, phosphorus, arsenic, antimony, bismuth).
In special cases, e.g., high voltage switches, gases with good dielectric properties and very high breakdown voltages are needed. Highly electronegative elements, e.g., halogens, are favored as they rapidly recombine with the ions present in the discharge channel. The halogen gases are highly corrosive.
Bulk insulators block conductive heat transfer and convective flow either into or out of a building. Air is a very poor conductor of heat and therefore makes a good insulator. Insulation to resist conductive heat transfer uses air spaces between fibers, inside foam or plastic bubbles and in building cavities like the attic.
Generally for elements that operate higher than 600 °C, ceramic insulators are used. [8]: 137 Aluminum oxide, silicon dioxide, and magnesium oxide are compounds commonly used in ceramic heating element insulators. For lower temperatures a wider range of materials are used.
Diamond is a good electrical insulator, having a resistivity of 100 GΩ⋅m to 1 EΩ⋅m [32] (1.0 × 10 11 – 1.0 × 10 18 Ω⋅m), and is famous for its wide bandgap of 5.47 eV. High carrier mobilities [33] and high electric breakdown field [34] at room temperature are also important characteristics of diamond.