Difference Between Insulator and Resistor

In modern times, no city can function without electricity and no house can function without electric components and appliances, which makes it necessary to know the nature and properties of electricity in order to better understand how to make good use of it.

Insulators and resistors are both used to control current. Electricity can be very harmful if people come in contact with it and appliances can also get fried and catch fire if the excess current is allowed to flow to them.

Insulator vs Resistor

The main difference between insulator and resistor is that insulators are any substance that does not allow the flow of current or heat through them freely, or provides resistance to the flow of said things whereas resistors are electrical components made from insulators to control the flow of current in a circuit by being able to change resistance to the current flow.

Insulator vs Resistor

Insulators are substances that lack or have very few free electrons, therefore are poor conductors of electricity.

Insulation is a very necessary aspect of electrical devices since signals and current need to be isolated to their circuits in order to perform well, that is why electrical wires are embedded in a rubber coating, as rubber is an excellent insulator and prevents the flow of current outside the circuit.

Resistors are materials and devices made using the property of certain substances that do not let electricity flow freely through them

They are used to regulate the flow of current in a circuit by offering fixed and calculated ohms of resistance. They are important because high ampere current can cause fires and extensive damage if allowed to flow freely.

Comparison Table Between Insulator and Resistor

Parameters Of ComparisonInsulatorResistor
MeaningInsulators are substances the do not allow the flow of electricity through them.These are electrical components that partially allow a fixed amount of current to flow through them.
FunctionThey are used to prevent flow and heat and electricity outside of where they are supposed to be.They control the magnitude of current flowing through a circuit allowing only fixed current to flow.
ElectronsValence shell electrons are tightly bonded with the atoms and cannot flow.Valence shell electrons are somewhat loosely attracted, some can flow freely.
MaterialMaterials such as rubber, pure water, air, and wool are insulators.Materials such as carbon, ceramic, and metal oxides are resistors.
ResistanceThe resistance they offer is usually above 20 megaohms.Different resistors offer different resistance ranging from 1 ohm all the way up to 10 megohms.

What is Insulator?

An insulator is any substance that does not allow the flow of heat and electricity through it. They lack free electrons and it is a natural property of substances. Insulators are really important to protect humans from extreme cold as well as electric shocks.

Materials like air, pure water, rubber, cotton, wood, plastic, etc. are very good insulators. Therefore, insulators are used to make clothes, wire sheaths, and walls. In the case of insulators, the valence shell electrons are tightly bonded with the atom.

The atoms have  5 to 7 electrons in their outermost shell and therefore tend to attract more electrons to achieve their nearest noble gas configuration. This prevents the electrical energy to flow through it as there are no electrons to flow freely.

Insulators can be found everywhere in our daily lives, it is a really important property of physics, and even plants have evolved to develop insulation around themselves in hot climates to prevent excess water loss.

Materials that can trap air are excellent insulators. In general, metals are excellent conductors and poor insulators and most non-metals prove to be good insulators, that is why wires are made from metals and resistors are made from ceramics and carbon.

What is Resistor?

Resistors are electrical components made up of carbon and ceramic powder with resin that acts as an adhesive. The magnitude of the resistance offered by different resistors depends on the ratio of the carbon and the ceramic used.

Resistors allow some calculated amount of current to flow through them and are therefore used to regulate the amount of current that exists in a circuit.

Resistors are made up of substances that have no free electrons or very tightly packed electrons that cannot be separated from the atom, instead, these atoms want more electrons to achieve an inert state.

Resistance is defined as the property of substances by virtue of which they offer obstruction to the flow of current. This property is used in resistors to prevent high voltage in electrical devices because it may damage them.

Resistors not only change obstruction in a circuit but also control signal strengths, voltage division, etc. No electrical circuit board can be made efficiently without using several separate resistors either in parallel or in series.

In a series arrangement, resistance is added whereas, in a parallel arrangement, resistance is divided. Another appliance where resistors are the main components is a coil heater, where the filament gets very hot when current flows through it due to its high resistance.

Main Differences Between Insulator and Resistor

  1. An insulator is any substance that does not allow free flow of current whereas a resistor is a device that allows controlled flow of current through a circuit.
  2. A resistor is man-made using the property of resistance for electrical use whereas insulation is a natural property differing between different materials.
  3. Resistors are used in electrical appliances such as heaters, television, microwaves, etc. and insulators are used to coat wires, make clothes, heatproofing, and shockproofing.
  4. Resistors can offer resistance of any value that the resistor was made for whereas perfect insulators have an infinite resistance and allow no current flow.
  5. Substances like wool, cotton, air, pure water are insulators where as metalloids, carbon, metal oxides are resistors.
Difference Between Insulator and Resistor


All digital devices conduct signals in some way or form, and for maintaining the proper strength and frequency of these signals, understanding and using resistance properly is very important.

This is where resistors come in most handy. On the other hand, the signals also need to be in designated areas and paths and need to be isolated from the others to prevent interference, which is what insulators are used for.

In addition, insulators are really necessary for living beings to maintain normal body temperature, human and animal skin is also an excellent insulator, and so are the hair and fur of animals.


  1. https://journals.aps.org/prb/abstract/10.1103/PhysRevB.33.3020
  2. http://genesdev.cshlp.org/content/16/3/271.short
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