An infinitely long line of charge having linear charge density $\lambda$ lies at a distance $d$ from center of an imaginary sphere of radius $R$. Then 

Electric flux linked with the sphere is $\frac{2\lambda \sqrt{R^2-d^2}}{{\epsilon }_0},$ if $d<R$

If $d>R$, then the maximum value of potential difference between two points on the sphere is  $\frac{\lambda }{4\pi {\epsilon }_0}\ln \left(\frac{d+R}{d-R}\right)$

Electric flux linked with the sphere is zero if $d>R$.

If  $d>R$, then the maximum value of potential difference between two point on the sphere is  $\frac{\lambda }{2\pi {\epsilon }_0}\ln \left(\frac{d+R}{d-R}\right)$