Notes

Electric Field due to an Isolated Point Charge…

Electric Field due to an Isolated Point Charge – Electric field at a distance r from a source change q is given by
E = 1/4πε0 q/r2
For a positive charge (+q), vector E is directed radially outwards from it and for a negative charge (-q), vector E is directed radially inwards. Electric field due to a system of charges : Superposition of electric fields. The magnitude of the resultant of two electric fields is given by
(E = E21 + E22 + 2E1 E2 cosθ)
and its direction is given by
[tanα = E2 sinθ/E1 + E2 cosθ]