## Integral of electric field of dipole moment over a sphere at r = 0

1. The problem statement, all variables and given/known data

Can't get to the final equality ( integral = - 4*Pi/3).

2. Relevant equations
$$\int_V \mathbf{E }dV = - \int_F \frac{_{\mathbf{p}.\mathbf{e_{r}}}}{r^2}\mathbf{e_{r}}r^{2}d\Omega = \mathbf{p}\frac{-4\pi }{3}$$

3. The attempt at a solution

Can't find how to get -4Pi/3. In the way I am doing the r^2 would cancel out, the unit radial vectors would multiply each other to give one, and since p is the dipole moment vector and is constant in the problem (two point charges), it would get out of the integral. The integral over the solid angle d(omega) would then be equal to 4*Pi, and the answer would p*4Pi. Something is wrong here and I don't know what. Can anyone help?

Thanks

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