is perpendicular to xy plane Due to symmetry it depends only on distance form cantre, radial distance r=√x2+y2 At centre B1=
µ0I1
2R
and B2=
µ0I2
4R
clearly B2>B1 As we approach towards first loop B1 increases to infinity hence B1 dominates. So it would be zero at some point between inner loops and centre. Field will be in opposite direction inside and outside the loop.