# Problem: When is the electric flux on a section of a closed surface zero? a. When the electric field is in the direction of the section's area vector. b. When the electric field is in the direction opposite that of the section's area vector. c. When the electric field is perpendicular to the section's area vector.

###### FREE Expert Solution

Gauss law:

$\overline{){{\mathbf{\varphi }}}_{{\mathbf{E}}}{\mathbf{=}}{\mathbf{\int }}{\mathbf{E}}{\mathbf{·}}{\mathbf{dA}}{\mathbf{=}}\frac{{\mathbf{Q}}_{\mathbf{e}\mathbf{n}\mathbf{c}}}{{\mathbf{\epsilon }}_{\mathbf{0}}}}$

Integrating gauss law:

ϕE = E•Acosθ

The electric flux is zero if either E, A, or cosθ is zero.

94% (42 ratings) ###### Problem Details

When is the electric flux on a section of a closed surface zero?

a. When the electric field is in the direction of the section's area vector.

b. When the electric field is in the direction opposite that of the section's area vector.

c. When the electric field is perpendicular to the section's area vector.