Before revision: By definition and getting the electric field by the formula of electric field of an infinite line, where is charge , is the permittivity of free space, is the radial distance and is the unit vector in the direction away from the axis.
After revision: per unit lengthBy definition and getting the electric field by the formula of electric field of an infinite line, where is charge , is the permittivity of free space, is the radial distance and is the unit vector in the direction away from the axis.