Question

The earth has an electric field pointing radially down that averages 100 N/C. Thisfield is maintained by atmospheric processes, including lightning. What is the excesscharge on the surface of the earth ?

Answer 1

Answer:

Explanation:

Given

Average Electric Field Strength $E=100\ N/C$

Considering charge distribution to be uniform and earth to be symmetrical

Using Gauss law

$\phi =\oint \vec{E}\cdot \vec{dA}$

$\phi =E\cdot A_{sphere}$

Also  $E\cdot A_{sphere}=\frac{Q_{inside}}{\epsilon }$

here Electric Field is acting inward therefore

$Q=-\epsilon EA_{sphere}$

$Q=-8.85\times 10^{-12}\times 100\times 4\pi \times (6.37\times 10^6)^2$

$Q=-4.51\times 10^5\ C$