reading this section you will be able to do
a parallel circuit and explain how it compares to a series circuit.
a parallel circuit.
what a voltmeter does and how it is different from an ammeter.
Like the series circuit, parallel
circuits also contain a voltage (current) source as well as wires
and other components. The main difference between a series circuit
and a parallel circuit is in the way the components are connected.
In a parallel circuit the electricity has several paths that it
Try building this
simple parallel circuit
Congratulations! You have just built
a parallel circuit. Notice that when you closed the switch, the
electrons flowed through both loads at the same time. In our series
circuit, all the electrons flowed through all the components in
order. With the parallel circuit, some electrons go through one
load and some go through the other load, all at the same time.
At point A, the total current splits up and takes different paths
before the circuit joins back together again at point B.
A parallel circuit exists whenever
two or more components are connected between the same two points.
Those two points in this circuit are points A and B. Both resistors
connect to both points A and B.
Each parallel path is called a branch
of the parallel circuit.
Try building this
parallel circuit, now including a voltmeter
This parallel circuit contains 3 branches
(two resistors and a voltmeter), which means the electron current
goes through all three branches at the same time. We put a voltmeter
on this second circuit to show an important fact. In the last
4 circuits you made, you included an ammeter into them. Ammeters
must always be placed in series in a circuit, otherwise they will
not work. The voltmeter we added in the last circuit has a different
requirement in order to work. Voltmeters must be placed in parallel
with the circuit in order to work. This is because voltage meters
measure the difference in electromotive force (EMF) from one
area to another. They are used to measure the difference in EMF
on one side of a component compared to the other side of the component.
In our homes, most circuits contain 120 volts of EMF.
of the components are connected parallel with each other, they
form a parallel circuit.
must be wired in parallel in a circuit in order to measure the
difference in EMF from one point to another.