Initially, the current was zero, so self-induced flux was also zero. Now when we rotate the loop, the change in flux is

$\mathrm{\Delta }\mathrm{\varphi }=2\mathrm{\pi }{\mathrm{R}}^2\times \mathrm{B}$

Finally, to maintain the same zero flux, the current in the superconducting loop will be such that the flux due to induced current will negative of the flux due to external field

$\mathrm{L}\times \mathrm{i}=2\mathrm{\pi }{\mathrm{R}}^2\times \mathrm{B}$.

$\mathrm{i}=\frac{2\mathrm{\pi }{\mathrm{R}}^2\times \mathrm{B}}{\mathrm{L}}$