The inside loop is pulled radially outward. The outside loop is pulled radially inward.
Work Step by Step
Parallel wires that carry current in the same direction attract one another. Every segment of the inner loop has a nearby element of the outer loop carrying a parallel current, attracting it outward. The effects of the other parts of the outer loop either cancel due to symmetry, or are weaker due to distance. The net effect is that the inside loop is pulled radially outward, toward the outer loop. (If the inner loop were made of a stretchable conductor, it would become a larger circle.) By a similar argument, and invoking Newton’s third law, the outside loop is pulled radially inward, toward the inside loop. (If the outer loop were made of a compressible conductor, it would become a smaller circle.)