\[E=k\frac{q}{r^2}\]
Variables
Eelectric field magnitude (N/C)
kCoulomb constant (N*m^2/C^2)
qpoint charge (C)
rdistance from charge (m)
Description
What is this formula?
This formula calculates the magnitude of the electric field generated by a point charge at a given distance.
When to use it
Use it when analyzing electric fields produced by isolated charges in electrostatics problems.
Example
Data:
k = 8.99e9 N*m^2/C^2
q = 5e-6 C
r = 0.20 m
Formula:
E = k*q/(r^2)
Substitution:
E = (8.99e9*5e-6)/(0.20^2)
Result:
E = 1.12e6 N/C
Applications
Electrostatics, capacitor analysis, particle physics, electric field calculations, and electrical engineering.