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General
Easy
Question
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields 
(sold line) and 
(dashed line). If 
is larger than , which of the following graphs shows the correct variation of R with T in these fields? 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 
(0). An interesting property of superconductors is that their critical temperature becomes smaller than (0) if they are placed in a magnetic field, i.e., the critical temperature (B) is a function of the magnetic field strength B. The dependence of (B) on B is shown in the figure.
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields?
The correct answer is:
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