Electric Field Intensity Due To A Point Charge
Suppose we have to calculate electric field intensity at any point P due to a point charge q at O, where OP= r.
Consider a small positive test charge q0> at P.
According to Coulomb’s law, force at P is
F = 1/4Пεo qq0/r2 ar
where ar is unit vector directed from q towards q0.
As E = F/q0
Therefore by putting value of F in above equation, we get
E = 1/4Пεo q/r2 ar
This is the expression for electric field intensity due to a point charge.
Note: Try to make the diagram for this problem yourself. If you are able to understand this article, then you can answer the following questions:
1. What is the force due to a point charge?
2. What is the electric field intensity due to a point charge?
Reference: This article is referred from my authored book “concepts of electromagnetic field theory” having ISBN 978-81-272-5245-8. In case of any doubt in this article or any other EMFT or physics related article, kindly post in the comment section.