Electric field due to a charged particle at a random point in space

[Lukasz]

Can we calculate the electric field at any given point in space even if there are no charged particles there? The equation for electric field given in a standard EM course is kqq0/q0r^2 where q0 is a test charged impacted by the electric field. How about just any point in space?

 

[jtbell]

The equation for electric field given in a standard EM course is kqq0/q0r^2 where q0 is a test charged impacted by the electric field.

No, that's the equation for the electric force acting on q₀.

The electric field produced by the source charge q, at the location of q₀, is E = kq/r², regardless of whether q₀ is actually at that location or not.

When you put q₀ at that location, it experiences a force F = q₀E.

 

[Lukasz]

I think I posted an equation for an electric field as I included q0 in both nominator and denominator, and thanks for explaining, I thought so.

 

[jtbell]

Oops, I saw the q₀ in the numerator but missed the one in the denominator.