We know that,

The energy stored per unit volumeenergy density) in an electric field E is given by

Where,

E=magnitude of electric field intensity

ϵ₀=absolute permittivity of vacuum

As we know that,

And the electric field due to a point charge Q at a distance r is given by

Therefore, energy density by formula)

And E

∴

⇒

Thus , the energy density in the electric field created by a point charge falls of with distance from a point charge as