Superconductors are materials that carry electrical current with exactly zero electrical resistance. This means you can move electrons through it without losing any energy to heat.

Superconductors require very cold temperatures, on the order of 39 kelvins (minus 234 C, minus 389 F) for conventional superconductors. The solid mercury wire that Kamerlingh Onnes used required temperatures below 4.2 K (minus 269.0 C, minus 452.1 F).

Superconductors are materials which transport electric charge without resistance1 and with the display of associated macroscopic quantum phenomena such as persistent electrical currents and magnetic flux quantization.

Superconductivity is the weird phenomenon of zero electrical resistance that occurs when some materials are cooled below a critical temperature. The best superconductors have to be cooled with liquid helium or nitrogen to get cold enough (often as low as -250 °C or -480 F) to work.

Superconductor material classes include chemical elements (e.g. mercury or lead), alloys (such as niobium–titanium, germanium–niobium, and niobium nitride), ceramics (YBCO and magnesium diboride), superconducting pnictides (like fluorine-doped LaOFeAs) or organic superconductors (fullerenes and carbon nanotubes; though …

And superconductors are those materials which are usually bad conductors in room temperature but when the temperature is decreased to very low, the resistance becomes zero. That’s why good conductors can’t be transformed into superconductors.

Type I superconductors are those superconductors which loose their superconductivity very easily or abruptly when placed in the external magnetic field. Type II superconductors are those superconductors which loose their superconductivity gradually but not easily or abruptly when placed in the external magnetic field.

This is also the reason why good conductors at room temperature which are close to these in the periodic table–for example; copper, silver, platinum, and gold–do not become superconductors at low temperatures: the interactions between the lattice and the valence electrons are simply too weak.

Originally Answered: Why superconductivity is observed at low temperature ? Resistance of a conductor is directly proportional to the temperature. Hence the resistivity decreases on decrease in temperature. Therefore superconductivity is observed at extremely low temperatures.

The exchange of energy makes the material hotter and randomizes the path of the electrons. By making the material cold there is less energy to knock the electrons around, so their path can be more direct, and they experience less resistance.

When lead, mercury and certain compounds are cooled to extremely cold temperatures, they become superconductors. They stop showing any electrical resistance and they expel their magnetic fields, which makes them ideal for conducting electricity.

When a superconductor’s temperature drops below the critical temperature, its resistance: drops to zero. Materials having resistance changes as voltage or current varies are called: nonohmic.

In a superconductor, below a temperature called the “critical temperature”, the electric resistance very suddenly falls to zero. This is incomprehensible because the flaws and vibrations of the atoms should cause resistance in the material when the electrons flow through it.

The critical temperature for superconductors is the temperature at which the electrical resistivity of a metal drops to zero. The transition is so sudden and complete that it appears to be a transition to a different phase of matter; this superconducting phase is described by the BCS theory.

Theoretically it is possible to have a resistor with a zero resistance. But practically it is not possible to have a resistor with zero resistance. A resistor with a zero resistance will be called a perfect conductor.

• 0.05 N – NaCl. C.
• 0.1 N – NaCl. Medium. Answer. Correct option is. C.

Resistance can never be 0 though. When the resistance in any circuit is equal to zero then the current passing through that circuit will be infinite. We know from Ohm’s law that V=IR. Here, if you consider resistance as zero then the equation becomes V=I(0). …

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Resistance also depends on the material of the conductor. The resistance of a conductor, or circuit element, generally increases with increasing temperature.

The resistance increases as the temperature of a metallic conductor increase, so the resistance is directly proportional to the temperature.

What happens to resistance when length is doubled? From the equation, we understand that resistance is directly proportional to the length of the conductor and inversely proportional to the crossectional area of the conductor. Doubling the length doubles the resistance.

As the length increases, the number of collisions by the moving free electrons with the fixed positive ions increases as more number of fixed positive ions are present in an increased length of the conductor. As a result, resistance increases.

The resistance of any conductor is directly proportional to length and inversely proportional to area of cross-section of the substance. As value of resistance(R) is directly proportional to length of resistance, so by increasing the length of resistance the value of resistance increases.

The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through. The relationship between resistance and wire length is proportional .

The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size.

Resistivity depends on the temperature of the material. This hinders the flow of electrons, and the resistivity increases.

Larger cross sections have less resistance, and longer conductors have more resistance. Therefore, by multiplying resistance by area and dividing by length, you get a value for a material property (resistivity ρ) that doesn’t depend on the size of the conductor.

As resistance is inversly proportional to area. When thickness increases the e- movement become little free and therefore charge movement become possible. Hence resistance decreases.

Expert Answers Therefore resistance increases with the length. When cross sectional area increases the space of the elctrons to travel increases(simply explained). Therefore less amount of obstacles for the current. Therefore when area increases the resistance decreases.

Also, resistance is an aspect that opposes the flowing of free electrons. In contrast, resistivity is any material’s property that tells the resistance of the material with a particular dimension….Difference between Resistance and Resistivity.

The resistivity of the conductor is inversely proportional to the area of the conductor.