Museum Entrance

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Museum Entrance
Ch 17 Electricity
Chapter Review
Electric Charge Static
Electrical Energy
Electric Current
Circuits
Room Five
Curators Offices
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Curators Office
Created by Mrs. Childers 7th per. AC Class

• Content Standards
• S8P5
• Students will recognize characteristics of
  gravity, electricity, and magnetism.
• 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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Room 1
Electric Charge Static
Electrical Force Electric Field
Static Electricity Discharge
Moving Charges
Conduction, Induction, Friction
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Room 2
Electric Current
DC
AC
Resistance
Voltage
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Room 3
Generating Electrical Energy
Kinds of Cells
Parts of a Cell
Photocells
Thermo- couples
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Room 4
Circuits
Series Circuits
Parts of A Circuit
Household Circuit Safety
Parallel Circuits
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Room 5
Chapter Review
Level II
Level I
Answer Key
Level III
Super Nova Ultimate ? Of the Year
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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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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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Conduction, Induction, Friction
Induction- A 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 couldnt function. Friction- a 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. Conduction- When 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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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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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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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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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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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 objects resistance
depends on the objects material, thickness,
length, and temperature. The higher resistance,
the lower the current.
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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

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ells/How-Fuel-Cell-Works.jpg
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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

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  et_cel0.gif
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  0-004-EC128E8C.gif

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Thermocouples
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/Q18-Relfow/Thermocou
ples_Large.jpg
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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

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OCEL.JPG
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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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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
• 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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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
• 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.

Linked citation goes here
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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 -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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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
c. valence electrons b. 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 c.
insulation b. induction d.
friction 5. What occurs when an uncharged
metallic object is charged with out contact?
a. induction c. electroscope b.
static charge d. conduction
6. What unit are electric currents expressed in?
a. AC and DC c. watts b. amps
d. electrons 7. What is the opposition
to the flow of electric charge? a. voltage
c. resistance b. friction
d. electric current 8. Resistance is expressed
in what unit? a. joules c. volts
b. watts d. ohms 9. What connects the parts
of a circuit together? a. wires
c. current b. 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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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. Whats the difference between
wet and dry cells? a. no difference
b. Wet cells have electrolytes
and the other doesnt 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 arent 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 cant
d. Power Time Electrical
energy. 10. What is the standard voltage in an
outlet in the U.S.? a. 200v
b. 140v c. 90v
d. 120v
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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 doesnt 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

• 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?
• 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

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Answer Key
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Super Nova Ultimate ? Of the Year
While waking up you scrape against your rugged
carpet and then your favorite jazz song comes on
and you start doing the moon walk but you bump
into you shag rug carpet walls and cause your cat
to fall off the fan and 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, the tread mill is going
so fast you try to hold on to the bars while your
feet skid on the rubber then when you couldnt
hold on any longer you let go and rammed into a
wall you feel very strange then you walk to leave
your room when you touch the door knob everything
goes black.

• How many electrons did you loose?
• Everything is still dark
• When did I get shag rug walls?
• I see a light
• 2000 volts.
• I dont own a cat
• Darn raccoon
• 4 volts

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