Electrical resistance of certain materials, known as superconductors, changes abruptly…

Electrical resistance of certain materials, known as superconductors, changes abruptly from a nonzero value to zero as their temperature is lowered below a critical temperature T_C(0).
An interesting property of superconductors is that their critical temperature becomes smaller than T_C(0) if they are placed in a magnetic field, i.e., the critical temperature T_C(B) is a function of the magnetic field strength B. The dependence
of T_C(B) on B is shown in the figure.


A superconductor has T_C(0) = 100 K. When a magnetic field of 7.5 Tesla is applied, its T_C decreases to 75 K. For this material one can definitely say that when