Why does the wire of an electric heater not glow while the heating element does?

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Because the heating element is made of alloy which has high resistance whereas cord is made of copper or with any other low resistance material.

Because the heating element is of shorter length whereas cord is of longer length.

Because the heating element is not insulated whereas cord is insulated.

None of the above

answer is B.

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Detailed Solution

According to Joule's law of heating,
Heating is directly proportional to the resistance of the material. The more the resistance, the more the heating.

H=I²RT

The heating element is made of alloy which has a very high resistance. Therefore, when the current flows at room temperature, It becomes very hot and red due to the heat produced by the current.
But the resistance the wire usually made of copper or aluminum has a very low resistance.

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