Question

58.5 million excess electrons are inside a closed surface. What is the net electric flux through the surface?.

Answer 1

Net flux through the surface = (net charge inside) / ε₀

and ε₀ = 8.85 x 10⁻¹² farad/meter.

What's the net charge inside the surface in this problem ?

It's (5.85 x 10⁷ electrons) x (the charge on each electron)

= (5.85 x 10⁷ electrons) x (-1.6 x 10⁻¹⁹ coulomb/electron)

= -9.36 x 10⁻¹² coulomb .

Finally, (net charge inside) / ε₀

= (-9.36 x 10⁻¹² coulomb) / (8.85 x 10⁻¹² farad/meter)

= -1.058 newton-m²/coulomb .