Units V/m represents which quantity?

Consider a spherical insulator of radius  2R that has uniform charge distribution. Find the flux through a spherical surface of radius  R centered at the center of the sphere in terms of total charge  of  2Q the sphere.

Four closed surfaces, S₁ through S₄, together with the charges -2Q, Q, and -Q are sketched in Figure . (The colored lines are the intersections of the surfaces with the page.) What is the flux through closed surface S4? 

When a piece of paper is held at an angle so that the plane of the paper makes an angle  41⁰ with the electric field, the flux through it  is 58.4 N.m²/C. Find the electric flux when the paper is turned so that the plane of the paper is perpendicular to the electric field. . Express your answer in units of N.m²/C  with one decimal place. Note that your answer should be positive.  

Electric potential difference between two points represents work on a unit charge by the electric field when the charge travels from the first point to the second.

A very thin metal spherical shell  has a total charge of +Q and a radius R. The electric potential of the sphere at a distance r from its center will have graph that looks like: