# Electrostatic field-Field lines relationship [duplicate]

How is the $$\frac{1}{r^2}$$ dependence of the electric field intensity due to a stationary point charge consistent with the concept of field lines?

## marked as duplicate by Feynmans Out for Grumpy Cat, Emilio Pisanty, ZeroTheHero, John Rennie, stafusaFeb 24 at 15:35

• Hi! Welcome to Physics Stack Exchange :) I am voting to close this question as of now as it is unclear what you are asking. Please elaborate on the specific question you want to ask. Thanks! :) – Feynmans Out for Grumpy Cat Feb 23 at 14:14
• – Emilio Pisanty Feb 23 at 14:52
• @EmilioPisanty No, that was not the answer I was looking for. Anyway, I worked it out yesterday using the concept of solid angles. I'll be posting my solution shortly. – Praveen K. Murugan Feb 24 at 12:04

Notice that, if you draw "equally spaced" electric field lines all coming from a single point, they must spread out equally in all directions. But the surface area of the sphere around the origin point is $$4\pi r^2$$, so the density of the field lines at some distance $$r$$ from the charge, which is their constant number divided by the surface area of the sphere of radius $$r$$, goes as $$1/r^2$$, as predicted.