39. The material used in electric heater is A.Tungsten B.Nichrome C.Brass D.Steel
Option B Solution: Most heating elements use Nichrome 80/20 (80% nickel, 20% chromium) wire, ribbon, or strip. Nichrome 80/20 is an ideal material, because it has relatively high resistance and forms an adherent layer of chromium oxide when it is heated for the first time. Material beneath this layer will not oxidize, preventing the wire from breaking or burning out. Hence, Nichrome is used as heating elements.
