What is an Insulator?
An insulator is a solid material whose inner electric charge does not drift freely, and therefore which does not conduct current under the impact of an electric field. Insulators are non-conducting materials. I.e. it resists electricity. It has great resistance value, usually in Mega ohms.
Properties of insulators
- It has large resistance and specific resistance.
- Large di-electric strength.
- High Mechanical strength
- Resisting high temperature.
- May not get change in nature due to temperature.
- It should not absorb water
- Can be made to any shape.
Classification of Insulators
In general Insulators are categorized into three types: They are:
Hard Insulators – e.g. Back lite, porcelain, Wooden Plank, Glass, Mica, Ebonite.
Soft Insulators – e.g. Rubber, Poly-vinyl chloride, varnish coated papers, Micanite.
Liquid Insulators – e.g. Mineral oil, Shellac, Varnish.