Differential resistance and critical current distribution in an Ag-clad (BiPb) 2Sr 2Ca 2Cu 3O 10+y tape

V- I characteristics of well characterised Ag-clad BPSCCO tape have been studied in the temperature ( T) range 80-106 K and magnetic fields ( B) up to 60 mT. The zero field critical current density at 77 K was about 10 000 A cm ^-2. The variations of J _c with B ( B^-0.5) and T[( {1 - T}/{T _c}) ^1.3] probably arise from the intragranular flux creep. The magnitude and the variation of the differential resistance ( R_ƒ) of BPSCCO core with T are consistent with those arising from the flux flow in low B. Very wide distribution of critical currents (CCD) within the core is tentatively ascribed to a broad distribution of the flux pinning energies in BSCCO.