One of the main disadvantages of copper cables is that copper is expensive compared with other metals such as iron or aluminum. Copper can also corrode, though not as much as some other metals.
Leaving aside superconductors: graphene, silver, copper.
superconductors
Earthquakes
Expense
It doesn't. Superconductors have no (virtually no) losses, they are purely inductive. This has no bearing on how current flows. Normal conductor will heat up due to resistive losses of the line (I^2 R losses), while a superconductor shouldn't.
They are usually quite expensive and require very low operating temperatures.
Normal conductors have resistance which restricts the flow of electricity and wastes some of the energy as heat. The resistance increases with the length of the conductor. Superconductors have close to zero or zero resistance and a few other properties, but the resistance is the most important one because it means electricity can flow more efficiently through it. The drawback is that all the superconductors we know of today have to be cooled down to EXTREMELY low temperatures to achieve superconductivity.
Because at present all superconductors must be super-cooled in a coolant such as liquid nitrogen to become superconductors.
Resistance decreases with the decrease of temperature. Superconductors are made by lowering the temperature.
A drawback is a disadvantage. Thus, the opposite (or antonym) of "drawback" is "advantage"
Because refrigerating superconductors to the cryogenic temperatures needed by current ones is expensive, severely limiting the applications they are used in.Metallic superconductors need cooling to the temperature of liquid helium.Copper oxide ceramic superconductors need cooling to the temperature of liquid nitrogen.Room temperature superconductors, if they exist, would need little or no cooling.
In a way, all currently existing superconductors are "low-temperature", but some more so than others. The traditional superconductors work up to about 20 K (or minus 253 Centigrade); more recent "high-temperature superconductors" work up to 100 K or so. 100 K is still minus 173 Centigrade, but it is much "hotter" than the traditional superconductors. The new "high-temperature" superconductors apparently work different than the old-fashioned ones; at least, the theory that explains the traditional superconductors fails to explain how the new superconductors work.
In superconductors, no electricity is wasted because there is no resistance to the flow of electrons. In conductors any electricity not used, is wasted.
Franklin Curtis Mason has written: 'The tunnel effect in superconductors' -- subject(s): Superconductors
Anatoli Larkin has written: 'Theory of fluctuations in superconductors' -- subject(s): Fluctuations (Physics), Superconductors
Superconductors float due to the Meissner effect, which causes them to repel magnetic fields, allowing them to levitate above a magnet.
Superconductors are materials that let current or electricity pass through them. Insulators are materials that don't allow current or electricity to pass through them. Superconductors are mostly all metals. Insulators are wood, plastic, and paper.