Electric Field
Electric Field (E) is a property of space induced by the presence of electric charge in the vicinity.
Definition: Electric Field at a point in space is the net Force that exerted by all the other charges in the vicinity on a unit point charge put there.
Units: E is measured in Newtons/Coulomb.
To calculate E at a point: Imagine a 1-Coulomb charge is there and apply Coulomb’s Law.
Notes:
Rather than thinking of Coulomb’s Law as describing simply the force that one charged particle exerts on another, the field concept is that an electric charge modifies the physical properties of the space around it in such a way that another charge placed in that space will feel a force. We call the property of space “the field,” and think of the field itself as producing the force. This is very similar to the concept of the gravitational field, which Einstein thought of as actually a curvature of space.
Since field is force per unit charge it’s SI units are SI unit of force divided by SI units of charge.
Note: Electric field is a vector. That is, it has both magnitude and direction.