Physics, Electricity, Magnetism, Science, Math.
integration. Because our surface is closed, we used ∮ symbol instead of “∫” symbol. φ = ∮E*dA*cos θ………..(1) The integration in (1) is not as easy as it looks. Both E and θ change over each point on the surface. E depends on the distance r from the +q charge. As the distance from the charge varies