Answer 1:
Your question is very interesting. If we
mathematically analyze it, we have to make clear
that the answer is different when the voltage
arising from a changing magnetic field is held
constant, than when it is a varying one (as when you move the magnet back and forth in a simple harmonic motion). Here you also have to consider that the resistance R in a superconductor is zero, R=0 (a characteristic of conducting metals when
they behave as a superconductors), then all the
results will depend on the voltage, the inductance
of the wires and time.
In the first case, when the voltage is constant (there is not a change of magnetic field), the current in the superconductor increases without a boundary (which is unrealistic, since the magnetic field would also have to increase without boundary (Faradays law)). This situation does not happen with a copper conductor, which has a current limited by the voltage and the value of the resistance.
In the case when the voltage is a varying
one, the current in the superconductor will
increase more than the current in the copper coil,
but it will be directly limited by the magnitude of the voltage, and inversely limited by the inductive effect and the frequency at which the voltage signal moves. The magnitude of the current will be given by: Voltage/(inductance x 2pi x
frequency of voltage signal) Then,
replacing the copper coil with a superconductor
Type-2 coil, will make a higher current, but will
still be limited by the rate of changing magnetic
field. |