49. Intext questions XVII

 

The heating element of an electric heater is made of a high resistant alloyhigh conductance alloylow resistant alloy. When a large amount of voltagechargecurrent is passed through the heating element, it reaches a high temperaturelow temperaturehigh voltage and becomes hot. This makes the heating element glow red.

 

The cord of an electric heater is usually made of copper or aluminiumiron or aluminiumcopper or lead. These materials have high resistancelow resistanceno resistance, and hence, the cord does not glow.