it says, N Integrate has evaluated to non-numerical values for all sampling points in the region with boundaries {{0,20}


when I run the code it says,NIntegrate has evaluated to non-numerical values for all sampling points in the
region with boundaries {{0,20}

\[Chi][b_] := (Z/k1)*NIntegrate[Subscript[f, pp1][q]*Subscript[F, pp1][q]*BesselJ[0, q*b]*q, {q, 0, b}] +  (Nn/K1)*NIntegrate[Subscript[f, pn1][q]*Subscript[F, pn1][q]*BesselJ[0, q*b]*q, {q, 0, b}]   data = Table[{b, \[Chi][b]}, {b, 0, 5.1, 0.1}]