After
reading this section you will be able to do
the following:
Define
a series circuit, and list the components needed to make it.
Construct
a simple and complex series circuit.
Define
what a load is.
Try building this
simple series circuit
In the interactive box (applet) below,
you will need to place the correct circuit components (i.e. battery,
light bulb, etc.) on the correct diagram symbol by dragging them
with your mouse.
Congratulations! You have just built
an electric circuit. Notice that when you close the switch to
complete the electrical circuit, the electrons start moving and
the ammeter indicates that there is current flowing in this circuit.
Also notice that the light bulb begins to glow. This happens because
the electrons moving through the tiny wires in the bulb (or filament)
make them become so hot that they glow. If there is any air inside
the light bulb, the filament wires will burn up.
What you have just created is something
called a series circuit. This is called a series circuit
because there is only one path for the electrons to take between
any two points in this circuit. In other words, the components,
which are the battery, the switch, the ammeter, and light, are
all in “series” with each other.
Load defined
The light bulb is considered a load
in this circuit. You might think of a load as anything
that is using the energy that is being delivered by the electric
current in a circuit. It could be anything from a light bulb to
a computer to a washing machine and so on.
Try building a
series circuit with resistors
Let’s build another series circuit,
but this time we will use some resistors instead of a light
bulb. Resistors are components that are used to control that amount
of current flowing in a circuit. The light bulb in the first circuit
was actually acting like a resistor because it only allowed a
certain amount of current to flow through it. If there are no
resistors or components that act like resistors to slow the flow
of electrical current, too much current may flow through the circuit
and damage its components or wires. Too much current flowing through
a component results in the generation of heat that can melt the
conductive path through which the electrons are flowing. This
in known as a short circuit and is the reason fuses or circuit
breakers are often included in a circuit.
Congratulations! You have just build
a more complex series circuit. We cannot see any work being done
since there is no light bulb, but there is current actually flowing
inside. We know the current is flowing because the ammeter is
indicating this. It is important to know that we may not be able
to tell whether current is flowing through a circuit without test
equipment, such as our ammeter connected to the circuit. Electricity
can be very dangerous and experiments like these should never
be conducted without adult supervision. Never work with electricity
unless you are trained to know how to work with it safely.
Review
When all
the components are in line with each other and the wires, a
series circuit is formed.
A load
is any device in a circuit that is using the energy that the
electron current is delivering to it.
