At what temperature, in terms of the critical temperature , is the critical field of a superconductor one-half its value at ?
Measurements of a superconductor’s critical magnetic field at various temperatures are shown in the accompanying table. Determine the value of the critical magnetic field at absolute zero. Assume a critical temperature value of 7.2 K.
A tightly wound solenoid at a temperature of 4.2 K is 60 cm long and is constructed from a Pb wire of radius 1.6 mm. Find the maximum current that the solenoid can carry at which the wire remains superconducting. Use a value of 7.2 K for the critical temperature and use a value of 0.080 T for the value of the critical magnetic field at absolute zero.