106er = cosθz + sinθcosφx + sinθsinφy,
θ is angle from z axis and φ is angle from x-axis
and dl = (-sinφx + cosφy)*(adφ)
dl x B = (sinφcosθy - sinθsin2φz +cosθcosφx - sinθcos2φz)*(Ba dφ)
if you integrate wrt φ from 0 to 2π then the terms involving sinφ and cosφ will be zero
only thing left is Ba z ∫02π(-sinθ)dφ
= -2πBasinθ z
to calculate sinθ = d(a2+d2)0.5
NOTE : i have used spherical coordinates. you can look them up in wiki
otherwise you will have to use symmetry to argue that x and y components of the force will be zero as it is symmetric. and then calculate only the z component of the force.