Difference Between Conductor & Insulator

The conductor and insulator are the types of material. One of the major difference between the conductor and insulator is that the conductor allows the energy (i.e., current or heat ) to pass through it, whereas the insulator does not allow the energy to pass through it. Some other differences between them are explained below in the form of the comparison chart.

Content: Conductor V/s Insulator

  1. Comparison Chart
  2. Definition
  3. Key Differences
  4. Point to Remember

Comparison Chart

Basis For ComparisonConductorInsulator
DefinitionMaterial which permits the electric current or heat to pass through it.Restrict the electric current or heat to pass through it.
Electric FieldExist on the surface but remain zero inside the conductor.Do not exist on insulator.
Magnetic FieldStore energyDo not store energy
Potential Remain same at all the point on conductor.Remain zero.
Thermal ConductivityHighLow
Covalent bondWeakStrong
ConductivityVery highLow
ResistanceLowHigh
ElectronsFreely moveDo not move freely
ResistivityVary from high to lowHigh
Temperature coefficientPositive temperature coefficient of resistanceNegative temperature coefficient of resistance
Conduction bandFull of electrons Remain empty
Valence BandRemains EmptyFull of electrons
Forbidden gapNo forbidden gapLarge forbidden gap
Examples Irons, aluminum, silver, copper, etc. Rubber, wood, Paper, etc.
Application For making electrical wires and conductor As a insulation in electrical cables or conductor, for supporting electrical equipment etc.

Definition of Conductor

The conductor is defined as the material which allows the electric current or heat to pass through it. The electrons in a conductor freely moved from atom to atom when the potential difference is applied across them. The conductivity of the conductor depends on the number of free electrons in the outermost shell of the orbit. The conductivity of the material is directly proportional to the number of free electrons.

The conductivity of the material is directly proportional to the number of free electrons.The valence band and conductance band of a conductor are overlapped each other and hence there is no forbidden energy gap. The resistance of the conductor is very low due to which the charges freely move from place to place when the voltage is applied across them. Copper, aluminium, silver, mercury, etc. are some of the examples of the conductor.

Definition of Insulator

The materials which do not allow the electric current or heat to pass through it such type of material is called an insulator. The covalent bond between the atoms of an insulator is very strong.Thus, the electrons or charges do not move freely. The resistivity of the insulator is very high.

The forbidden gap between the valence band and conduction band of an insulator is very large, and hence the electrons require large energy for moving from valence band to conduction band.

The insulator is mainly used for separating the conductor and for supporting the electrical equipment. It is also used in an electrical cable. Paper, wood, porcelain, etc., are some of the examples of an insulator.

Key Differences Between Conductor and Insulator

  1. The conductor is the type of material which allows the electric current or heat to pass through it whereas the insulator does not allow the electric current or heat to pass through it.
  2. The electric field exists only on the surface of the conductor, and it remains zero inside the conductor whereas it does not exist on an insulator.
  3. The conductor, when placed in a magnetic field do not store energy whereas the insulator stored energy in a magnetic field.
  4. The thermal conductivity of the conductor is high, whereas the thermal conductivity of the insulator is low.
    • Thermal conductivity is the property of the material which allows the heat to pass through it without any obstruction.
  5. The covalent bond between the atoms of a conductor is very weak whereas in an insulator it is very strong.
    • The covalent bond is the chemical bond between the atoms which involve the sharing of electrons.
  6. In conductor, the electrons freely move from atom to atom whenever a potential difference is applied across it whereas, in an insulator, the electrons are fixed due to atomic level forces.
  7. The conductivity of the conductor is high, whereas the conductivity of the insulators is low.
    • Conductivity is the rate at which the heat or charge flows through the material.
  8. The resistance of the conductor is very less, and hence the electrons freely move from atom to atom. The resistance of the insulator is very high.
  9. The conductor has a large number of free electrons whereas insulator does not have a large number of free electrons.
  10. The potential on the conductor remains same at all the point whereas in insulators the potential remains zero.
  11. The resistivity of the conductor varies from high to low whereas the resistivity of an insulator is very high.
    • Resistivity is the resisting power of the material.
  12. The conductor has positive thermal coefficient of resistance whereas the insulator has the negative thermal coefficient of resistance..
    • The thermal coefficient of resistance describes the change in the physical property of the material with temperature. If the resistance increases with the temperature, then it is called the positive thermal coefficient of resistance. In negative thermal coefficient, the resistance decreases with the increase in temperature.
  13. The conduction band of a conductor is full of electrons whereas the conduction band of an insulator is empty.
  14. The valence band of a conductor is empty whereas the valence band of an insulator  is full of electrons.
  15. There is no forbidden gap in conductor whereas the forbidden gap in an insulator is very large.
    • The forbidden gap is the gap between the valence band and the conduction band of material. It determines the conductivity of the material. If the gap is small, then the electron is easily moved from the valence band to the conduction band and hence the material is considered as a conductor. If the gap between them is large, then the material is express as an insulator.
  16. Copper, silver, aluminium, mercury are the examples of the conductor. The wood, paper, ceramic etc., are the examples of an insulator.
  17. The conductor is used for making electrical wires and cables.The insulator is used for separating the current carrying conductors and for supporting the electrical equipment.

Point to Remember

According to IACS (International Annealed Copper Standard), the silver is considered as the most conductive material. But the cost of the silver is very high and hence it is not used for making electrical wires and cables.

10 thoughts on “Difference Between Conductor & Insulator”

  1. what is the difference between combustibility and conductivity? my students want to know why wood and plastic are good insulators, whereas glass is not, yet both wood and plastic will burn before the glass. Can you help? thanks, laura jones

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