ELECTRIC FIELD AND LINES OF FORCE

Electric field:-

The electric field is a region or space surrounding a charge in which electrostatic force can exist.

The electrostatic force is of repulsion for similarly charged bodies and of attraction for dis-similarly charged bodies which are placed in that region.

Just like magnetic lines of force to represent the influence of a magnet upon its surroundings, similarly in electrostatics, we imagine electrostatic lines of force to exist around an electric charge.

These lines are taken as beginning from a positive charge and terminating at a negative charge. 

They differ from the magnetic lines of force, in the sense that electric field lines do not form a closed circuit.

In M.K.S. system one line of force is assumed to be emanating from a unit charge or q lines of force from from a charge of q units, whatever be the surrounding insulating media.

These lines of force radiate from the charge uniformly in all directions.

Lines of force also indicate the path which a positive charge would take if it were placed near a charge of +q units and were free to move.

The arrows indicate the direction of movement of such a charge.