The energy density in the electric field created by a point charge falls off with the distance from the point charge as

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KollegeApply · Accepted Answer

1/r^4 Energy density U is given by U = $\frac{1}{2}$∈_0E^2.......(1) The electric field created by a point charge at a distance r is given by E = q/(4pi∈_0r^2) On putting the above form of E in eq. 1, we get U = $\frac{1}{2}$ ∈_0(q/(4pi∈_0r_2))^2 Thus, U is directly proportional to 1/r^4

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