The invention of electric lines of force was done by famous scientist Michael Faraday. These do not provide the full info about electric field, but provide us with quantitative partial information.
Def: Electric lines of force can be defined as a way or path, it may be straight or curved, so that the tangent at any point to it gives the direction of the electric field intensity at that point.
Line AB below in figure is an electrostatic line of force. So the tangent to the line p will give us the direction of electric field intensity
at point P.
Similarly if at other point Q tangent AB is drawn it will give us the direction of
The above tangent lines are showing a truth, but the main point to be noted is that in actual the lines of forces don’t exist in real.
Electric lines of force due to a positive charge are directed outwards. It is shown in the figure below. These lines have no limit. They are simply pointing towards infinity.
But in case of negative charge instead of going away from the charge the lines of force are directed inwards.
Now the figure below is showing the lines of forces producing due to equal and opposite charges.
The charges which are same and equal are pushing electric force of lines with equal force. So, electric lines of forces are not even touching each other.
Lets do an another experiment by taking unequal charges. Let’s take a bigger charge and other smaller one. The bigger charge will apply greater force on the electric lines of the charge than the charge which is smaller in magnitude.
In last case we have taken a sheet of positive charge. Let’s see the electric lines of field in this case.
