Electricity

                One of the first steps to understanding electromagnetism is by understanding electric charges and the electric field.  Put simply, an object can have one of three electrical properties.  It can be: neutral (no net charge), positive or negative.  A positive object possesses exactly that, a net positive charge.  A negative charge is the opposite.  Understanding electric charges will help us to understand the electric field. 

Every object is composed of atoms.  Atoms, generally, have both positive and negative charges.  Electrons possess a negative charge and hold the power of transforming an object back and forth between the three electrical properties.  If an object has a surplus of electrons it is negatively charged, if an object has a deficit of electrons it is positively charged, and if an object has neither a deficit nor surplus of electrons it will be neutral.  Note, a neutral object still consists of atoms and therefore charges.  The possession of these properties allow us to look at the relationship between positive and negative charges.

Positive, negative, and neutral objects exhibit a few key properties towards one another.  The first property is that same charges/objects repel and opposite charges/objects attract.  This means that two positive charges or two negative charges will repel each other.  A positive charge and a negative charge will attract each other.  A neutral object will attract both a positive and a negative charge.  This is because in some objects, electrons are free to move and transform the charge from positive to negative.¹  These attractive and repulsive forces are exactly that, forces.

            A charged object has an effect on other charged objects around it.  “The space around a charge is altered to create the electric field.”  This is the concept of the electric field.  The electric field of two charges will have a beginning and an end.  The field begins, or flows out of a positive charge and ends, (flows into) on a negative charge.  The field exists around every point of a charge.²  Charged particles are one way of creating an electric field. 

An electric field can also be created by a changing magnetic field.  This is known as the induced electric field.³  The electric field forms perpendicular to the magnetic field.⁴  The electric field can be visualized as concentric circles forming around a rod. 

            A key aspect of an electric field is that it exerts a force on charged particles.⁵  To keep things simple, let’s assume we have an electric field radiating from an object.  This object will have a positive net charge.  Now let’s place a positively charged particle next to the object.  The particle will want to move away from the object.  This is because the two repulse each other.  Therefore, we say an electric force has been exerted on the particle in the electric field.  Even though electricity and magnetism are separate issues at this point, they compliment each other quite well.