State Gauss’ theorem. Draw a graph showing the variation of electric field, as one moves from the centre of a charged metal ball to a point on its surface and then to a far-off outside point. 

A cylindrical Gaussian surface has its axis along an infinite line of uniformly distributed positive charges, as shown.

(i) For which surface is the electric flux zero?

A cylindrical Gaussian surface has its axis along an infinite line of uniformly distributed positive charges, as shown.

Over which surface is $\overrightarrow{E}$ zero?

A cylindrical Gaussian surface has its axis along an infinite line of uniformly distributed positive charges, as shown.

Over which surface is $\left|\overrightarrow{E}\right|$ constant?

A cylindrical Gaussian surface has its axis along an infinite line of uniformly distributed positive charges, as shown.

Over which surface does $\left|\overrightarrow{E}\right|$ vary?

Charge q is enclosed in a hollow cylinder. If the electric flux through the curved surface of the cylinder is ${\mathrm{\Phi }}_C$, then determine the electric flux through either plane surface of the cylinder.