Question

Is this equation for current in a superconductor correct?

Answer 1

Assuming we have kept a constant source of voltage, is the current gained through an ideal conductor given by I=2Vq2tmI=2Vq2tm where qq is the charge per volume of the carrier and mm is the mass per volume and tt is the time for which the circuit has been switched on? I have worked this out by equating the velocity given by kinetic energy multiplied by qq to the current and power as IVtIVt. I think this makes sense since both the area and length of the wire do not affect how much resistance to motion electrons face. Moreover, wouldn't this mean that in order to keep a constant voltage, the power supplied by the battery (P=2V2q2tmP=2V2q2tm) would increase over time to infinity? That is, unless it is the power that's kept constant.

We could put this as the 'resistance' at least to defined by ohms law in a superconductor is m2q2tm2q2t.

Answer 2

Explanation:

Superconductivity is the set of physical properties observed in certain materials, wherein electrical resistance vanishes and from which magnetic flux fields are expelled. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.[1][2][3][4]

• This phenomenon was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911, in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical mystery. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.