english: Well, first there are strands of magnetic field left inside, but now the superconductor doesn't like them moving around, because their movements dissipate energy, which breaks the superconductivity state.
non_english: Najprv tam ostanú vlákna magnetického poľa, ale supravodiču sa nepáči, keď sa pohybujú navôkol, pretože ich pohyb spotrebúva energiu, čo prerušuje stav supravodivosti.