1electrostatic potential energy and nature of force
KQ1Q2 (apply sign of charge) repulsive force for U=+ve attractive force U=-ve
2system of charge potential energy
K(Q1Q21 + Q2Q32 +Q1Q33)
3n charges equation for number of pair
n(n-1)/2
4work done against electrostatic force
W=Uf-Ui
5electrostatic potential
V=KQ =W/q (apply Q with sign)
6zeo potential point (what is the condition and equation)
KQ1/(r-x)=KQ2/x (inside point apply without sign,|Q1|>|Q2|) KQ1/(r+x) = kQ2/x (outside point)
7potential due to conducting sphere
v outside=kQ Vsurface=kQ/R Vinside=kQ/R
8charge distribution ratio
Q1'/Q2'=R1/R2 sigma1/sigma2 =R2/R1 E1/E2= R2/R1
9charge distribution equation
Q1'=(Q1+Q2)R1/(R1+R2) ,Q2'=(Q1+Q2)*R2/(R1+R2)
10work with potential and charge
W=q(v2-v1)