Electrical Conductor vs Insulator
Electrical insulation and electrical conductance are two of the most important properties of matter. In fields like electrical engineering, electronic engineering, electromagnetic field theory, and environmental physics, the insulation properties and conduction properties of matter have a great significance. Since our economies are run by electricity, it is vital to have a good understanding of such matters. Some of our day to day phenomena can be described using the conductance and insulation of matter. In this article, we are going to discuss what electrical conductance and electrical insulation are, what are the theories behind electrical conduction and electrical insulation, their similarities, what are the materials showing respective property, daily phenomena involving conductance and insulation, and finally their differences.
Electrical conductors are defined as materials with free charges that could move. In this context, since every material has at least one free electron due to thermal agitation every material is a conductor. This is true in theory. However, in practice conductors are materials that would let certain amount of current to pass through them. Metals have metallic bonding structure, which is a positive ion engulfed in a sea of electrons. A metal donates all its outer shell electrons to the electron pool. Therefore, metals have a high amount of free electrons so they are very good conductors. Another way of conduction is the hole flow. When an atom in a lattice structure releases an electron, the atom becomes positive. This vacant electron shell is known as a hole. This hole can take up an electron from the neighboring atom causing a hole in the neighboring atom. When this shift is continued this becomes a current. Ions in the ionic solutions also act as current carriers. All our electrical power lines are made up of conducting metals. Metals and salt solutions are good example for conductors. If the conductance of a conductor is low it means the medium is resisting the current flow. This is known as the resistance of the conductor. The resistance of the medium causes an energy loss in the form of heat.
Electrical insulators are materials that do not have any free charges. But in practice, every material has some free electrons due to thermal agitation. A perfect insulator would not let a current pass even if the voltage difference across the terminals is infinite. However, a normal insulator would let current pass after a few hundred volts. When a high voltage is applied across an insulating material, the atoms inside the material would polarize. If the voltage is sufficient, electrons will be separated from atoms to create free electrons. This is known as the breakdown voltage for this material. After the breakdown, there will be a current flow due to the high voltage. Distilled water, mica and most of the plastics are examples of insulators.
What is the difference between Electrical Conductors and Insulators?
• Electrical conductors have zero or very little resistance, while electrical insulators have very high or infinite resistance.
• Conductors have free charges, while insulators don’t have free charges.
• Conductors let current through, while insulators do not.