BASIC AUTOMOTIVE ELECTRICITY
Learning Objective: Describe the basic principles of
electrical and magnetic theory. Identify the materials,
the devices, and the different types of electrical
circuits. Determine electrical measurements using
The basic principles of automotive electricity are
the essential knowledge required by the mechanic to
understand the operation of all-automotive electrical
systems and components. Unless you have a clear
understanding of these fundamental principles, you
will find it difficult to service the various electrical
components and systems encountered in the Naval
Construction Force (NCF). This understanding will
enable you to make sound decisions in the
troubleshooting process of all electrical systems.
BASIC PRINCIPLES OF ELECTRICITY
Learning Objective: State the basic principles of
electricity, the theory of electricity, and the composition
of electricity and matter.
All activity that takes place in any type of electrical
circuit depends on the behavior of tiny electrical
charges, called electrons. To understand the behavior
of electrons, we must investigate the composition of
matter. The electron is one of the basic electrical
components of all matter.
COMPOSITION OF MATTER
All matter, regardless of state (solids, liquids, and
gases), is made up of tiny particles, known as atoms.
Atoms combine in small groups of two or more to form
molecules; however, when atoms are divided, smaller
particles are created. These particles have positive or
negative electrical charges.
There are over 100 different basic materials in the
universe. These basic materials are called elements.
Iron is one element; copper, aluminum, oxygen,
hydrogen, and mercury are examples of elements. The
basic particles that make up all the elements, and thus
the entire universe, are called protons, electrons, and
neutrons. A proton is the basic particle having a single
positive charge; therefore, a group ofprotons produces a
positive electrical charge. An electron is the basic
particle having a single negative charge; therefore, a
group of electrons produces a negative electrical charge.
A neutron is the basic particle having no charge;
therefore, a group of neutrons would have no charge.
The construction of atoms of the various elements
can be examined starting with the simplest of
allhydrogen. The atom of hydrogen consists of one
proton, around which is circling one electron (fig. 1-1).
There is an attraction between the two particles,
because negative and positive electrical charges
always attract each other. Opposing the attraction
between the two particles, and thus preventing the
Figure 1-1.Composition of matter.