Choose the incorrect statement:
(a) The electric lines of force entering into a Gaussian surface provide negative flux.
(b) A charge $q$ is placed at the centre of a cube. The flux through all the faces will be the same.
(c) In a uniform electric field net flux through a closed Gaussian surface containing no net charge, is zero.
(d) When an electric field is parallel to a Gaussian surface, it provides a finite non-zero flux.
Choose the most appropriate answer from the options given below:
Answer: (D) (d) only
(a) Correct: entering lines make an angle greater than $90^\circ$ with the outward normal, giving negative flux.
(b) Correct: by symmetry each face gets $\dfrac{q}{6\varepsilon_0}$.
(c) Correct: by Gauss's law the net flux is zero.
(d) Incorrect: a field parallel to the surface is perpendicular to the area vector, so the flux is zero.
Solution by Sreeraj P, M.Sc Physics