Question: Electric charge produces a vector field E→, called the electric field, which represents the force on a unit positive charge placed at the point. Two positive or two negative charges repel one another, whereas two charges of opposite sign attract one another. The divergence of E→ is proportional to the density of the electric charge (that is, the charge per unit volume), with a positive constant of proportionality.
A certain distribution of electric charge produces the electric field shown in Figure. Where are the charges that produced this electric field concentrated? Which concentrations are positive and which are negative?
