Recent content by xBorisova

got it. thanks so much for your help :)

Thanks for the reply :) This is from notes written by my lecturer, I was just trying to understand his reasoning... It was in the derivation of total electrostatic energy due to a finite charge distribution, where he went from this expression U=1/2∫ρ(r)φ(r)dV to this one U=1/2∫εE2dV by means of...

could someone please explain why ∫(φE).dS (where φ is the potential and E is the electric field) is equal to zero in a general electrostatic case? Thank you

Could someone please explain how does this taylor expansion work: 1/|r-r'| ≈ 1/r+(r.r')/r3 possibly you have to taylor expand twice to get this result, an attempt at which led me nowhere, surely it cannot be this complicated. any useful comment about this would be greatly appreciated...