superconducting materials with DC solenoid problem

Resistivity of superconducting materials is almost zero, the resistivity of copper enameled copper resistivity. At room temperature, but can not make any conductors of a superconducting material, as

Temperature superconductors is usually -327 °.
    Or want to increase the magnetic force of the electromagnet, it must have a greater current power, a sufficient number of turns of the electromagnetic coil and a sufficiently large U-shaped core

, Magnetic Grate The specific needs complex calculations to calculate primary and secondary school is in an ideal condition, so the actual operation of a large deviation. Simply put, the line

The number of turns is proportional to the current size and magnetic, but too many turns, and the current will decrease, and this requires a large wire size (reduce the resistance, increasing current)

Increased diameter will increase the weight and volume, while providing enough power to a DC power supply. Various factors spurred the discovery and invention of the superconductor. magnetic bar But the super-

Conductor is an amateur can not be achieved under the conditions.