# What is electric field on the surface of a surface charge?

Electric field just near the surface of a surface charge is $$\dfrac{\sigma}{2 \epsilon_0} (\hat{n})$$ on one side and $$-\dfrac{\sigma}{2 \epsilon_0} (\hat{n})$$ on the other side.

What would be the electric field on the surface of a surface charge?

• How are you getting two different signs? If the surface is positively charged the field will be + on both sides (pointing away from the surface). If it is negatively charged, the field will be - on both sides (pointing into the surface). – Bob D Apr 24 '19 at 13:03
• w.r.t. our coordinate system, the unit vector has been inverted in the latter. – N.G.Tyson Apr 24 '19 at 13:24
• Is the surface positively or negatively charged? – Bob D Apr 24 '19 at 13:41
• well...if you consider the electric field the direction a test charge would move to... and you are in the plane of symmetry... – mikuszefski Apr 24 '19 at 14:17
• well, there is no on the surface. You are above or in the surface. Where would a test charge move to if it is in the surface? – mikuszefski Apr 25 '19 at 8:10