Specific Resistance (”ρ”) is a property of any conductive material, a figure used to determine the end-to-end resistance of a conductor given length and area in this formula: R = ρl/A. Specific resistance for materials are given in units of Ω-cmil/ft or Ω-meters (metric).
Heater resistance is the example for medium resistance.
Kilowatt Hour (kWh) is the commercial unit of electrical energy.; one kilowatt-hour is equivalent to 3.6 megajoule.
A positive temperature coefficient (PTC) refers to materials that experience an increase in electrical resistance when their temperature is raised. Materials which have useful engineering applications usually show a relatively rapid increase with temperature, i.e. a higher coefficient.
A negative temperature coefficient (NTC) refers to materials that experience a decrease in electrical resistance when their temperature is raised. The lower the coefficient, the greater a decrease in electrical resistance for a given temperature increase. Carbon is having negative temperature coefficient.