Download Parallel Circuits - Pine Mountain Middle School

Room
Five
Museum Entrance
Circuits
Electric Current
Chapter
Review
Electrical
Energy
Electric Charge &
Static
Ch 17
Electricity
Curator’s
Offices
th per. AC Class
Created by Curator’s
Mrs. Childers’
7
Office
Content Standards
S8P5
Students will recognize characteristics of gravity, electricity,
and magnetism.
a.
b.
Recognize that every object exerts gravitational force on every other and that the force exerted
depends on how much mass the objects have and how far apart they are.
Demonstrate the advantages and disadvantages of series and parallel circuits and how they transfer
energy.
c. Investigate and explain that electric currents and magnets can exert force on each other.
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Entry
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Electric Charge & Static
Static
Electricity
&
Discharge
Room 1
Electrical Force
&
Electric Field
Conduction,
Induction,
& Friction
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to
Entry
Moving
Charges
Electric Current
Room 2
AC
DC
Voltage
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to
Entry
Resistance
Generating Electrical Energy
Room 3
Parts of
a Cell
Kinds of
Cells
Thermocouples
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to
Entry
Photocells
Circuits
Room 4
Parts of
A Circuit
Series
Circuits
Parallel
Circuits
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to
Entry
Household
Circuit
Safety
Chapter Review
Room 5
Level II
Level I
Level III
Super
Nova
Ultimate
?
Of the Year
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to
Entry
Answer
Key
Static Electricity & Discharge
The Law of Electric Charges states that electric
charges that are alike will always repel, but
charges that are opposite will attract.
Static electricity is caused by a buildup of
negative electrons caused by two opposing
surfaces rubbing against each other in opposite
directions. Static electricity can be discharged
through direct contact or through indirect
contact and the attraction of opposite charges.
Linked citation goes here
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Exhibit
Electric Force & Electric Field
The force between charged objects is an
electric force. The size of the electric force
depends in two things, the amount of charge
on each object and the distance between the
charges. Charged things are affected by
electric force because charged things have an
electric field around them. An electric field is
the region around a charged object in which an
electric force is exerted on another charged
object.
Linked citation goes here
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Exhibit
Conduction, Induction, & Friction
InductionA process in which a shifting
magnetic field is used to create electric voltage.
Discovered by Joseph Henery & Michel
Faraday
This started a chain of events that led to
alternating current, and without that modern
technology couldn’t function.
Frictiona force that resists movement when
surface objects resist each other. No
movement will occur unless a force greater
then or equal to than the friction is applied.
ConductionWhen electrons move from one
object to another by direct contact
The first mechanical electrical generator, Michael
Faraday's magneto-electric induction apparatus
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Exhibit
Moving Charges
Moving charges are surrounded by magnetic
fields.
Moving charges experience force when they
move through fields.
Conductors are materials that charges can
move easily through.
For example, cables and wires are made of
metal. Electricity flows easily through metals.
Insulators are materials that charges cannot
move through easily.
For example, cables and wires are surrounded
by plastic. Electricity does not flow through
plastic easily, and the electricity does not reach
your hands.
Linked citation goes here
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Exhibit
AC
There are two kinds of electric current. The one
were talking about is alternating current (AC).
AC comes from electrical currents from outlets
in your home. Alternating Currents change
directions an amazing amount of times.
Actually in the U.S it changes directions up to
120 times every second! Usually AC goes
through cycles. Every time the alternating
current changes direction two times it goes
through cycles.
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Exhibit
DC
DC stands for direct current. Direct
current is measured in amperes
(amps) along with all other types of
currents. Direct current flows in
one direction through an electric
circuit.
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Exhibit
Voltage
Voltage is the strength of an electric
current and it is also potential difference
between two points in a circuit. It is
expressed in volts. It is important to know
that the symbol for volts is a capital “ v ”
(V). You can think of voltage as the
amount of energy released between two
points in the path of the electrical current.
The greater the voltage the greater
strength the current can be. Volts are
how battery companies measure the
strength of a battery.
Linked citation goes here
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Exhibit
Resistance
Resistance is the property of an electric
circuit element that causes the current to
convert power from electrical form to heat
when electric current flows through the
element. A resistor, a component
connected to an electric circuit, provides
resistance. An object’s resistance depends
on the object’s material, thickness, length,
and temperature. The higher resistance,
the lower the current.
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Exhibit
Parts of a Cell
•Cell: a device that produces an
electric current by converting
chemical or radiant energy into
electrical energy
•Cells contain a mixture of chemicals
•The chemicals, which are called
electrolytes, allow charges to flow
•Cells have a pair of electrodes
•Electrodes: the part of the cell that
is made from conducting materials
and allows charges to enter and exit
the cell
•Chemical energy is converted in to
electrical energy when chemical
changes between the electrolyte and
electrodes occur
http://cdnwww.greencar.com/images/hydrogen-fuelcells/How-Fuel-Cell-Works.jpg
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Exhibit
Kinds of Cells
•Cell: a device that produces an electric
current by converting chemical or
radiant energy to electrical energy
•Electrolyte: a mixture of chemicals that
allow charges to flow
•There are 2 types of cells; wet and dry
•Wet cells:
•Have liquid electrolytes
•Dry cells:
•Have solid or paste-like
electrolytes
•http://ventureinward.org/technology/review_files/wet_cel0.gif
•http://media-2.web.britannica.com/eb-media/90/24090-004EC128E8C.gif
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Exhibit
Thermocouples
•Thermocouple: a device that converts
thermal energy into electrical energy
•Made by joining 2 different metals
into a loop
•When the 2 different kinds of wires
are joined together it is called a
junction
•The temperature difference within the
loop causes charges to flow through
the loop
•The greater the temperature
difference, the greater the current
•Thermocouples do not generate much
energy
•Discovered by a German physicist
named T. J. Seebeck in 1821
http://www.datapaq.com/images/Q18Relfow/Thermocouples_Large.jpg
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Exhibit
Photocells
•Photocell: a device constructed to
change light energy into electrical
energy
•Contains silicon atoms
•When light shines on the photocell,
the electrons can move through a wire
to provide electrical energy to power a
device
•Photocells are commonly used in solar
panels
http://www.yourdictionary.com/images/compu
ter/_FOTOCEL.JPG
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Exhibit
Parts of a Circuit
All circuits need three basic parts:
•Energy Source can be a battery, a photocell, a
thermocouple, or an electric generator at a power
plant.
•Wires connect the other parts of a circuit.
•Loads: i.e.. Light bulbs, appliances, televisions,
and motors.
Linked citation goes here
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Exhibit
Series Circuit
Series Circuits: Use a single path to connect the
electric source or sources to the output device or
devices. If a series circuit is drawn on paper, a line
starting at any circuit part will pass through all the
other circuit parts only once before returning to
starting point.
•For example, the circuit in a two battery flashlight
connects the positive terminal of the second battery
touches the center terminal of the flashlight bulb. If
the switch is closed, the outer terminal of the bulb
touches the negative terminal of the first battery,
completing the circuit and lighting the bulb
Linked citation goes here
•Has a varying voltage depending on the number of
its power sources
•If one light bulb in a series circuit burns out, all the
others will as well because the burned-out bulbs have
opened the circuit.
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Exhibit
Parallel Circuits
Parallel Circuits: is a circuit in which loads are
connected side by side.
•Charges in a parallel circuit have more than
one path in which they can travel. Unlike the
loads in series circuits, a parallel circuit uses
the same voltage. So, all of the loads have the
same electricity content as the rest.
•You can connect different loads that need
different currents to the same circuit.
Uses:
Linked citation goes here
•Each branch works by itself
•If one load is broken or missing the other
branches still work.
•In a house, each electrical outlet is usually on
its own branch.
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Exhibit
Household Circuit Safety
Circuit Failure: Broken wires or water can cause a
short circuit. In a short circuit, charges do not go
through one or more loads in a circuit. The
resistance decrease, so the current increase. It
eventually starts heating, enough to start a fire.
Fuses and circuits breaker can help prevent fires
from starting.
Fuses: Charges in a circuit flow through a thin strip
of metal in the fuse. If the current is too high the
metal strip melts and the circuit is broken.
Circuit Breakers: A switch that automatically opens
if the current is too high, is called a circuit breaker.
When the strip of metal in the breaker warms up, it
bends and opens the switch which opens the circuit.
Electrical Safety Tips:
Linked citation goes here
-Make sure the insulation on cords is not worn down.
-Do not overload circuits by plugging in too many
electrical devices.
-Never put objects other than a plug in a electrical
outlets.
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Exhibit
Level I
1. Opposites are to attract as likes are to…….
a. repel
b. turn over
c. attract
d. conduct
2. Protons and …… are included in the
nucleus.
a. electrons
b. valence electrons
c. neutrons
d. charges
3. What are the three ways that an electric
charge can be received?
a. electric discharge, friction, conduction
b. electroscope, lightning, induction
c. friction, conduction, induction
d. law of electric charges, static, polar bears
4. What occurs when two objects are rubbed
together in opposite directions?
a. conduction b. insulation
c. induction
d. friction
5. What occurs when an uncharged metallic
object is charged with out contact?
a. induction
b. electroscope
c. static charge d. conduction
6. What unit are electric currents expressed
in?
a. AC and DC b. watts
c. amps
d. electrons
7. What is the opposition to the flow of
electric charge?
a. voltage
b. resistance
c. friction
d. electric current
8. Resistance is expressed in what unit?
a. joules
b. volts
c. watts
d. ohms
9. What connects the parts of a circuit
together?
a. wires
b. current
c. electrons
d. switch
10. What does a switch do?
a. cuts the wire
b. opens and closes the circuit
c. keeps the wire straight
d. provides extra power
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Exhibit
Level II
1. What is AC/DC?
a. An awesome Rock band
b. A measure of resistance
c. direct currents and alternating currents
d. Parts of a cell or battery
2. Thermal energy can be converted into energy by
use of a?
a. Thermocouple
c. Thermal converter
b. Thermal Cell
d. Thermal conductor
3. What is one way that you can conserve energy in
your household?
a. Use bigger toasters
b. Leave your cell phone charger plugged into the outlet.
c. Use a fan instead of A/C
d. Use ceramic heaters
4. What is the effect of thickness and length on
a. The time it takes for energy to flow
b. Whether the circuit is open or closed.
c. No difference at all.
d. Determines the type of current it has.
5. What’s the difference between wet and dry cells?
a. no difference
b. Wet cells have electrolytes and the other doesn’t
have liquid electrolytes.
c. They make up batteries
d. Dry have solid or paste like electrolytes.
6. What does a solar panel use to convert light
energy to electrical energy?
a. batteries
b. Fuses
c. thermocouples
d. photocells
7. What is one thing you can do to protect
yourself from electricity?
a. wear oven mitts
b. Make sure insulation cords aren’t worn
c. Wear metal gloves
d. Throw a banana at it.
8. What do cells do to make electrical energy?
a. nothing
b.. Discharges
c. change chemical or radiant energy
d. it collects electrolytes
9. How do you determine the electrical energy?
a. With an electroscope
b. Electrical energy = Power x Time
c. You can’t
d. Power ÷ Time = Electrical energy.
10. What is the standard voltage in an outlet in
the U.S.?
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a. 200v
b. 140v
Exhibit
c. 90v
d. 120v
Level III
1. What happens to the metal leaves of an electroscope when
it is electrically charged?
a.
b.
c.
d.
2. What is an electric field?
a. the force of attraction or
repulsion
b. the space around a charged object
c. opposites attracting and likes repelling
d. the moving of electrons by electrons
3. What is an electric current?
a. a current that moves 120 times a second
b. a current that has 60 cycles a second
c. the rate at which charges pass through a given point
d. a current that uses the outlets at your home
4. What is a parallel circuit?
a. a circuit in which all parts are connected in a single loop
b. a gap between two pieces of conducting material
c. a circuit in which the electricity doesn’t reach the battery
again
d. a circuit in which loads are connected side by side
5. If the circuit is too hot on the fuse, than the fuse…….?
a. melts
b. becomes frozen
c. transforms into a different element
d. goes through sublimation
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Exhibit
6. A GFCI primarily acts as a small…….
a. power source
b. fuse
c. switch
d. circuit breaker
7. In a short circuit, charges do not go through
one or more……..
a. switches b. loads
c. circuits
d. electroscopes
8. Electrolytes allow ….. to flow.
a. cells
b. superconductors
c. electrode d. charges
9. When the resistance in an object reaches 0
ohms, they are called …..?
a. superconductor
b. electrodes
c. electrons
d. electrolytes
10. What is an electrode?
a.
the part of a cell where charges enter and
exit
b. the part of a cell that changes radiant energy
to electrical
c. a type of circuit breaker
d. mixes with electrolytes so charges flow
easier
Answer Key
•
Level 1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
A
B
C
D
A
B
C
D
A
B
Level 2
1.
A&C
Level 3
2.
A
1.
A
3.
C
2.
B
4.
A
3.
C
5.
B
4.
D
6.
D
5.
A
7.
B
6.
B, D
8.
C
7.
B
9.
B
8.
D
10.
D
9.
A
10.
A
Super nova ?
Super Nova Ultimate ? Of the Year
While waking up you scrape against your
rugged carpet and then your favorite jazz song
comes on. You start doing the Moon Walk but,
you bump into you shag rug carpet walls and
cause your cat to fall off the fan. Your cat
freaks out causing you to gain more static
electricity from the friction of his claws on your
face. Then you jump on the tread mill tread mill
which is going so fast. You try to hold on to
the bars , but your feet skid on the rubber.
When you can’t hold on any longer you get
rammed into the wall. You feel very strange as
you walk toward the door. When you touch the
door knob everything goes black.
How many electrons did you
loose?
A.
Everything is still dark…
B.
When did I get shag rug
walls?
C.
I see a light…
D.
2000 volts.
E.
I don’t own a cat…
F.
Darn
raccoon
Linked
citation goes here
G.
4 volts
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Exhibit