two ground balls deep in the ground

elektricke_pole1 J (r = a) = \frac{I}{4 \pi a^2}

E (r = a) = \frac{I}{4 \pi \sigma} \frac{1}{a^2}

U_p = \int_a^{x \rightarrow \infty} E (r) \mathrm{d} r = \frac{I}{4 \pi \sigma} \int_a^{x \rightarrow \infty} \frac{1}{r^2} \mathrm{d} r = \frac{I}{4 \pi \sigma} \Big( \frac{1}{a} - \frac{1}{\infty}\Big) = \frac{I}{4 \pi \sigma a}

R_{p1} = \frac{U_p}{I} = \frac{I}{4 \pi \sigma} \frac{1}{a}

 

 

 

elektricke_pole2