Electric lines of force (also known as field lines ) is a pictorial representation of the electric field. These consist of directed lines indicating the direction of electric field at various points in space.
There is no rule as to how many lines are to be shown. However, it is customary to draw number of lines
proportional to the charge. Thus if number of lines are drawn from or into a charge , number of lines would be drawn for charge
The electric field at a point is directed along the tangent to the field lines. A positive charge at this point will
move along the tangent in a direction indicated by the arrow.
Lines are dense close to a source of the electric field and become sparse as one moves away.
Lines originate from a positive charge and end either on a negative charge or move to infinity.
number of lines are drawn from or into a charge 
, 
number of lines would be drawn for charge 
