# Irodov Solutions : Problem 3.6

The statement of the problem is :

## A positive point charge 50μC is located in xy plane at a point with position vector rₒ = 2i + 3j, where i and j are the unit vectors along the x and y axes. Find the electric field strength vector E and its magnitude at the point with position vector r = 8i - 5j. Here rₒ and r are expressed in meters.

The question is based on a simple application of Coulomb's Law (in vector form) to find the electric field intensity vector due to a point charge. Observe the diagram and calculations given below.
Hence the sought electric field strength vector is

**E**= [2.7**i**- 3.6**j**] kV/m and its magnitude E = 4.5 kV/m.