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As we know that magnetic flux in a superconducting loop flux cannot changed at all as resistance is zero often we see in books that superconducting material the external magnetic field are not shown passing through it . Which i agree upto some point when maybe no current is intially in the loop and the external magnetic field is then switched on , but can there be a situation where field lines may be there inside the loop of external field?

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Yes, assuming the loop is initially not superconducting, any flux lines threading the loop will be trapped when the loop does become superconducting. Once the flux is trapped like that, it cannot change since the voltage induced in response to any change would cause infinite circulating current (since the loop has zero resistance). Attempts to change the flux threading the loop by applying an external field will be thwarted by a change in the circulating current exactly sufficient to cancel any of the external flux that would otherwise thread the loop.

(Note that there are limits to how much flux and current a superconductor can sustain.)

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