Question

Q.The value of $ E.da over a closed surface is zero. It is possible that
(a) Electric field is nonzero at all points on the surface
(b) The direction of electric field is towards outside at all points of the surface.
(c) There are charged particles inside the closed surface
(d) Electric field is towards outside at some points of the closed surface and towards inside at
some other points.
a
b
С
d​

Answer 1

Answer:

Using Gauss's law the flux of the electric field through closed surface is ϕ=∮E.ds=ϵ0Qenclosed

So if the electric field is zero everywhere, then the flux may be zero.

if charge inside the closed surface is zero, then flux must be zero.