If a closed surface encloses no net charge, what is the net electric flux through the surface?

If a closed surface encloses no net charge, what is the net electric flux through the surface?

• A. 0
• B. ε0
• C. 4π ε0
• D. Q_enclosed / ε0

Answer: (A)

Net flux is determined by Gauss’s law: the total outward electric flux through a closed surface equals the enclosed charge divided by ε0. If no net charge is inside, the enclosed charge is zero, so the net flux must be zero. Field lines can still cross the surface, entering and leaving in equal amounts, but their contributions cancel, yielding zero outward flux. The other expressions would require a nonzero enclosed charge or reflect a different unit convention, which isn’t the case here.

Net flux is determined by Gauss’s law: the total outward electric flux through a closed surface equals the enclosed charge divided by ε0. If no net charge is inside, the enclosed charge is zero, so the net flux must be zero. Field lines can still cross the surface, entering and leaving in equal amounts, but their contributions cancel, yielding zero outward flux. The other expressions would require a nonzero enclosed charge or reflect a different unit convention, which isn’t the case here.