Question

Of which material an electrical resistance made of ? which are used to make several electrical appliances for example UPS,computer,TV.

Answer 1

In the market the commercial resistors are carbon resistors.The resistive elements are made from a mixture of finely powdered carbon and an insulating material usually ceramic and a resin holds the mixture together. Carbon composite resistors are very cheap to make and are therefore commonly used in electrical circuits. However, due to their manufacturing process carbon type resistors have very large tolerances so for more precision and high value resistances,film type resistors are used instead.