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

This question was in our textbook: 'Why does the heating cord of an electric heater not glow while the heating element does glow when electric current passes through it?'. All I have been taught is alloys do not oxidize readily, hence they are used in common heating appliances like toasters and heaters. I understand that the heating element is made of an alloy which dissipates huge heat due to higher resistance and hence a part of the heat energy transforms to light energy in the heating element. But I am very much confused about the heating cord. Can anyone please explain me about the heating cord-What is its purpose in an electric heater? And what material is it made of?Any help is appreciated. Please feel free to correct any mistakes. Courtesy of AnnaV : By heating cord your book probably means the wire or flex which conducts electricity from the power supply to the heater. This is made of copper because it has very little resistance to current, compared with the resistance of the heating element, which is very high. The electrical power dissipated in a resistance $r$ when current $I$ flows through it is $I^2r$. The same current flows through the wire and the element, but the resistance of the element is very much larger. Very little electrical energy is dissipated in the wire so it does not get hot and does not glow - unlike the heating element.

Table of Contents • • • • • • • • Why do the wires connecting to an electric heater to the main not glow while its heating element does? The heater’s heating element is made up of an alloy that has very high resistance, so when current flows through the heating element, it becomes too hot and glows red. But the cord’s resistance, which is usually of copper or aluminium, is low, so it does not glow. Why does a wire made of Nichrome glow while as copper wire does not? The heating element of an electric heater is made of an alloy which has high resistance whereas the cord is made of copper metal which has very very low resistance…now,the heating element of an electric heater made of nichrome glows because it becomes red hot due to the large amount of heat produced on passing … Why does the coil of electric heater? A coil is a heating element attached to the heating unit itself. The heater generates the electric current which flows into the coil. The heating coil transfers the electric energy into heat energy. It may be directly immersed in the medium to heat it up or radiate heat through an open space. Which wire is used in heating coil? Nichrome Nichrome, a non-magnetic 80/20 alloy of nickel and chromium, is the most common resistance wire for heating purposes because it has a high resistivity and resistance to oxidation at high temperatures. When used as a heating element, it is usually wound into coils. Why same current heat the heating coil but produce negligible heat in ...

The heating element of the heater is made up of an alloy, which hashigh resistivity and thereby has high resistance.So, when current flows through the heating element, its temperature increases and itglows red. In this way, the heating element converts the electrical energy into heat energy. But the resistivity of the material ofcord whichis usually made of copper or aluminium is very low thereby its resistance is low as it is used to carry the electric current to the heating element.Therefore, the heat gained is very low. So, it does not glow.

Why does the cord of an electric heater not glow while the heating element does ? Ans: The cord of an electric heater is made of thick copper wire and has much lower resistance than the heating element. For the same current (I) flowing through the cord and the element, heat produced in the element is much more than that produced in the cord. As a result, the element becomes very hot and glows whereas the cord does not becomes hot and as such does not glow. Also Read : • Why does the cord of an electric heater not glow while the heating element does ? • What is the heating effect of electric current ? • The work function of a photosensitive element is 2 eV. Calculate the velocity of a photoelectron… • An electric kettle has 750 W-240 V heater, is plugged to a 200 V mains. If heat capacity of kettle… • An element a decays into element C by a two step process • A cord is wrapped around the rim of a solid cylinder of radius 2.25 m and a constant force of 40 N… • A rubber cord catapult had cross-sectional area 25 mm^2 and initial length of rubber cord is 10 cm.… • A sphere is accelerated upwards by a cord whose breaking strength is four times its weight. The… • The half-life period of a radioactive element x is same as the mean life time of another radioactive… • A 100 W and a 500 W bulbs are joined in series and connected to the mains. Which bulb will glow…

Why Does the Heating Element Glow While the Cord of the Heater Doesn’t? It is a matter of common experience when the element of the heater connects to the electric supply, It becomes hot and starts to glow after some time. This effect is known as the heating effect of electric current or the Joule effect. In this case, two additional points are noticeable viz, • The heater element glows but not the cord of the heater • Heating elements glow but not melts Why Does the Heating Element Glow but not the Cable Connect to it? Generally, the heating elements of stoves, water heaters, and other electric heaters are made-up of alloys or elements having a very high resistance, resistivity (specific resistance “ρ”), and positive temperature coefficient “α” such as Tungsten, Nichrome, etc. On the other hand, the power cords, cables, and flex wires are made of elements or alloys having very high conductivity such as Copper, Silver, Aluminum (which has very low resistance, etc. To understand the basic concepts, let’s see what is resistance and conductance of a material. • Resistance “represented by the symbol of Ohm “ Ω” is the property of a material that opposes the flow of electrons (electricity) through it. In other words, the ability of a circuit or material to oppose electric current is known as resistance. • Conductance “represented by the symbol of Mho “ ℧” or Siemens ( S) is the ability of a circuit or material to permit electric current flow in it. In other words, the reciproca...