What is the equation of electric field?

The electric field ( E ) is defined as the force ( F ) per unit charge ( q ) experienced by a positive test charge placed in the field, expressed mathematically as ( E = \frac{F}{q} ). It can also be calculated using Coulomb's law for point charges, given by ( E = \frac{k \cdot |Q|}{r^2} ), where ( k ) is Coulomb's constant, ( Q ) is the source charge, and ( r ) is the distance from the charge. The direction of the electric field is away from positive charges and towards negative charges.