Electrostatic Induction in Metals vs Insulators

[rdjohns12]

If we have a small dielectric sphere and a point charge, they will experience an attractive force due to electrostatic induction. (From the elongation/rotation of charges bound to individual atoms).

Likewise, if we have a small metallic sphere and a point charge, they will experience an attractive force due to electrostatic induction. (From the displacement of the electron gas).

Can I accurately say that the attractive force for the metallic case is always greater than or essentially equal to the attractive force in the dielectric case?

I think this because the screening in conductor is perfect (i.e. infinite kappa), so the induced charge distribution will be large enough to cancel the entire field from the charge, whereas in the dielectric, the screening can be much worse or (for high kappa materials) at best approximately as good.

I have never seen this written down in quite the way I am asking it, so I am not sure if I am wrong.

 

[anuttarasammyak]

You can investigate the electric field generated at the point of the charge for both the cases to confirm your hypothesis.