Current flow through the total parallel circuit
will be equal to the current flow through any
individual series circuit component.
The disconnection or the burning out of the
series components will completely disable the
entire circuit, whereas a failure of any of the
parallel circuit components will leave the
balance of the circuit still functioning.
Short circuit (fig. 1-14, view B). A short circuit
occurs when copper touches copper, such as when
wiring insulation between two wires fails and the
wiring makes contact.
REVIEW 3 QUESTIONS
Q1. Voltage is known by what term?
Open circuit (fig. 1-14, view A). An open circuit is
a break or interruption in the circuit, such as a wire that
has come loose or a slipped connection that is not
making contact. But the expression of an open circuit is
not only used when wire connections are actually
separated as in a switch but also when the resistance in
the wiring circuit is so that no current can flow between
the battery and the unit it operates. A good example of
such a condition is rust and corrosion that forms and
accumulates at a battery cable or terminal.
Ground circuit. A ground circuit occurs when any
part of the wiring circuit is touching the vehicle frame
inadvertently. A ground involves accidental or
unintentional contact between copper and the iron frame.
Q2. What are the three basic types of electrical
Q 3 . What type of circuit failure occurs when copper
Learning Objective: Describe the theory ofmagnetism
and the principles of electromagnetism and
Magnetic field is described as invisible lines of
force which come out of the North Pole and enter the
South Pole. For example, if iron filings were
sprinkled on a piece of glass on top of a bar magnet,
the filings would form themselves in curved lines
Figure 1-14.(A) Open circuit; (B) Short circuit.