Question

two special characteristics of nichrome wire

Answer 1

Because of its low cost of manufacture, strength, ductility, resistance to oxidation, stability at high temperatures, and resistance to the flow of electrons, nichrome is widely used in electric heating elements in applications such as hair dryers and heat guns...

Answer 2

Nichrome is basically a name given to nickel-chromium resistance wires. It is a non-magnetic alloy, which consists of 80 percent nickel and 20 percent chromium by weight, and is widely used in heating elements because of its relatively high resistivity. Out of the constituents of nichrome, nickel is an element with the chemical symbol Ni and atomic number 28, whereas chromium is an element with the symbol Cr and atomic number 24. Nickel is generally a silvery-white lustrous metal, and chromium, a steely-gray and hard metal. Nichrome, the alloy, is silvery-gray in color, resistant towards corrosion, and has a high melting point.

Physical Properties of Nichrome

The ultimate tensile strength of nichrome is 105,000 PSI (Pounds per Square Inch) and yield strength is around 50,000 PSI. Following are some of the other physical properties of nichrome.

Electrical Resistivity at room temperature: 1.0 x 10-6 to 1.5 x 10-6 ohm m

Thermal Conductivity: 11.3 W/moC

Magnetic Attraction: None

Thermal Expansion Coefficient (20oC to 100oC): 13.4 x 10-6/oC

Temperature Coefficient of Resistivity (25oC to 100oC): 100 ppm/oC

Specific Gravity: 8.4

Density: 8400 kg/m3

Melting point: 1400oC

Specific Heat: 450 J/kgoC

Modulus of elasticity: 2.2 x 1011