I did not understand the conclusion of the 6th paragrapgh which starts with "As you probably deduced," of the essay given on the link below:

http://www.physics.byu.edu/faculty/rees/220/book/lesson7.pdf

It is said that the difference is 4 times. How?

Question

I did not understand the conclusion of the 6th paragrapgh which starts with "As you probably deduced," of the essay given on the link below:

http://www.physics.byu.edu/faculty/rees/220/book/lesson7.pdf 

It is said that the difference is 4 times. How?

jamesj · Answer

As explained in the next paragraph, the choice of 4 is arbitrary, and just used for the purpose of explanation.  There are in reality an infinite number of field lines.  But this gives him a way to quantify the electric field strength in terms of the strength of the charges, q.