Question

Ten identical charges of amount 

7

 

μ

C

7 μC

 each are closed in a rectangular box. What is the electric flux through the box?

Answer 1

According to the Gauss's law, the electric flux $\Phi_E$ through the box is proportional to the total charge $Q$ enclosed within this box:

$$\Phi_E = \dfrac{Q}{\varepsilon_0}$$

where $\varepsilon_0 = 8.85\times10^{-12}F/m$.

The total charge is

$$Q = 10\cdot 7\mu C = 70\times 10^{-6}C$$

Substituting the numerical values, get:

$$\Phi_E = \dfrac{70\times10^{-6}}{8.85\times10^{-12}} \approx 7.91\times10^6V\cdot m$$

Answer. 7.91*10^6 V*m.