Explain the electrical contact materials with examples.
Electrical contact materials: A number of elements in their pure form as copper, nickel, palladium, molybdenum, platinum, tungsten and silver are mostly acceptable make and break contact materials. All elements' alloys mentioned also used for electrical contacts. Silver is a significant contact material. Copper added to silver decreased the cost of the contact material. While a combination of tungsten and silver results in a contact material comprises the advantages of the individual metals. A silver tungsten contact material will contain electrical conductivity and high thermal. Copper contacts are utilized in control relays, tap changers and motor starter switches. Copper contacts may be utilized for currents that are alternating current or direct current up to 500A and voltages (a.c or d.c) up to 600V. Contacts create of silver and silver alloys are broadly used. Silver has better resistance to oxidation compared to copper and can be utilized for voltages (a.c or d.c) up to 600V and direct currents up to 50A and alternating currents up to 200A. These contacts are used in all forms of industrial applications as generator cut outs, relays, thermal overload devices and also thermostatic control.