The invariance of the form of Maxwell's equations under Lorentz transformation can be used to derive the electric field of a uniformly moving point charge. The charge of a particle is considered frame invariant, as supported by experimental evidence. Alternatively the electric field of uniformly moving point charges can be derived from the Lorentz transformation of four-force experienced by test charges in the source's rest frame given by Coulomb's law and assigning electric field and magnetic field by their definition given by the form of Lorentz force. However the following equation is only applicable when no acceleration is involved in the particle's history where Coulomb's law can be considered or symmetry arguments can be used for solving Maxwell's equations in a simple manner. The electric field of such a uniformly moving point charge is hence given by: E = q 4 π π ε ε 0 r 3 1 − − β β 2 ( 1 − − β β 2 sin 2 ⁡ ⁡ θ θ ) 3 / 2 r , where q is the charge of the point source, r is the position vector from the point source to the point in space, β β is the ratio of observed speed of the charge particle to the speed of light and θ θ is the angle between r and the observed velocity of the charged particle.