Question

When a superconductor is placed in a weak external magnetic field H, and cooled below its transition temperature,

• A. the magnetic field is ejected
• B. the magnetic field get magnetized
• C. the magnetic field strength increased
• D. none of the above

Answer 1

Answer: (A)

When a superconductor is placed in a weak external magnetic field $H$, and cooled below its transition temperature, the magnetic field is ejected from it and this phenomenon is called effect Meissner effect. The ability of this expulsion effect of the magnetic field is determined by the nature of equilibrium formed by the neutralization within the unit cell of a superconductor.