Download SNC1D Types of Electrical Circuits PowerPoint

2017-03-28
Types of Electrical
Circuits
Mr. Masri
SNC1D Humberside C. I.
Think of all of the
different circuits in your
home.
How can one light be
turned on while another
one is turned off?
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The answer lies in the
way the circuits are
wired!
Circuits can be wired
in two different ways:
SERIES or PARALLEL
1. Series Circuit
A series circuit has only
one path for the
electrons to follow
(much like a race track).
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1. Series Circuit
Example:
+
_
2. Parallel Circuit
A parallel circuit has
multiple paths for the
electrons to follow
(much like city
streets).
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2. Parallel Circuit
Example:
+
_
Current in SERIES Circuits
Since there is only one path to follow, all of the
electrons must pass through every load in the
circuit before they can get more energy from the
power source
∴ the current through any load in the circuit is
exactly the same as the current through all of
the other loads in the circuit.
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Current in SERIES Circuits
Equation:
Itotal = I1 = I2 = I3 … etc
Current in PARALLEL Circuits
Since there are many paths to follow, the
electrons splits down each pathway; this
results in an uneven distribution of current
through the loads.
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Like 3 students walking different paths from
Humberside to Keele Station
Option 1
Option 2
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Option 3
Think of the students like electrons
Current in PARALLEL Circuits
∴  The sum of the currents through each of the
loads in the circuit will add up to the total
amount of current passing through all of the
branches in the circuit when the paths rejoin.
EQUATION: Itotal = I1 + I2 + I3 + … etc
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Potential Difference in
SERIES Circuits
As the electrons pass through successive loads
in the circuit, the potential difference in each
load will drop. Why?
Potential Difference in
SERIES Circuits
The total sum of all of the potential differences
in the loads will add up to the potential
difference of the power source.
Equation: Vtotal = V1 + V2 + V3 + … etc
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Potential Difference in
PARALLEL Circuits
The potential difference across any load in the
circuit is exactly the same as any other load in
the circuit (and the power source).
Energy only gets lost when the electrons
pass through a load.
Equation: Vtotal = V1 = V2 = V3 … etc
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VT = voltage gain at source
V1 = voltage drop at load 1
V2 =
“
“ “ “ 2
In Summary,
Series Circuit
V1
+ _
VT
IT
I1
IT = current out of source
I1 = current through load 1
I2 =
“
“
“ 2
I2
Mathematically,
VT = V1 + V2
V2
IT = I1 = I2
In Summary,
Parallel Circuit
Mathematically,
V1
V2
VT = V1 = V2
IT
I1
I2
IT = I1 + I2
+ _
VT
junction point
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Sample
Find V1
60 V
Solution:
+ _
120 V
30 V
VT = V1+ V2 + V3 (series)
120 V = V1 + 30 V + 60 V
V1 = 30 V
V1 = ?
Homework
! pg. 554 #1, 2, 4 and 6
! Series and Parallel Circuits handout –
diagrams on front – draw them and
complete problems on bottom of back
page
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