Question

Assume the magnitude of the electric field on each face of the cube of edge L- 1.07 m in the figure below is uniform and the directions of the fields on each face are as indicated. (Take El-31.8N/c and E,-23.5 NC.) E2 20.0 N/C 20.0 N/C Ei 20.0 N/C 50N/C (a) Find the net electric flux through the cube. N m2/c (b) Find the net charge inside the cube. (c) Could the net charge be a single point charge? O Yes O No

Answer 1

answer) a) we know the formula

$\phi$=EA

so at the top

$\phi$1=-23.5N/C*1.07²=-26.90515 N.m²/C

at the left side of the cube

$\phi$2=20N/C*1.07²=22.898N.m²/C

at the back side

$\phi$3=20N/C*1.07²=22.898Nm²/C

at the right side

$\phi$4=-31.8N/C*1.07²= -36.40782N.m²/C

at the bottom side

$\phi$5=15N/C*1.07²=17.1735N.m²/C

at the front side

$\phi$6=20N/C*1.07²=22.898Nm²/C

so the net flux through the cube=$\phi$1+$\phi$2+$\phi$3+$\phi$4+$\phi$5+$\phi$6=22.55 N.m²/C

so the answer is 22.6Nm²/C or 23 N.m²/C or 22.55Nm²/C

b) we have the formula

$\phi$e=qin/$\epsilon$₀

so qin=$\phi$e*$\varepsilon$_o=22.55*8.85*10^-12C²/Nm²=1.996*10^-10C

so the answer is 1.996*10^-10C or 2.00*10^-10C or 2.04*10^-10C

c) the correct option is=yes.

its because the flux through  the cube is not symmetrical.