Electricity and Magnetism
What is Electricity?
• A form of energy caused by
moving electrons.
Electricity TedEd
Charge: A buildup or shortage of electrons.
 Gaining or losing e-s develops a neg. or pos.
charge in an object.
 Charges exert forces (push or pull) on each
other.

Law of Electric Charges
 Like
(same) charges REPEL
 Opposite charges ATTRACT
Conductors
A conductor allows
___________/e-s to flow easily
 Some conductors are better than
others
Examples:
_______
Iron

Insulators

An insulator _______ electric
charges from _________ easily,
Examples:
Rubber
Cork
Wood
Plastic
Electric Current


Electric Current is the ______ of
electrons/charge through a
conductor_________
There are two types of electric
current:
__________ Current
_________ Current
Alternating Current (AC)


Changes __________ at a regular
rate.
Most commonly used type of
electricity because it does not
create as much heat.
Examples:
Powerplants
Houses
Christmas lights
Direct Current (DC)


Always flows in one _______.
Always flows from _________ to
positive
Example:
__________
 Creates a lot of heat
Resistance

__________ to current flow (anything
that ________ down current), mostly
a load.
Unit of measure is the ohm
Measured with an ohmmeter
Higher resistance would mean ______
(higher, lower) heat produced in a
circuit. Explain.
What is a circuit?
The path an electric current follows
 Consists of four parts:
1.___________:Something to get the
power from. Ex. ________, power line.
2. ______: Something that will use the
power
3. _______: To _______ the electricity
4. Switch: To open or _____ the circuit,
not ________. Current flows only through
a closed circuit. Brainpop on circuits

Simple Circuit diagram (copy on left page)
Scientists usually draw electric circuits using symbols;
cell
lamp
switch
wires

Give some examples of loads that
may be found in your kitchen.
In which of the following circuits will
the bulb NOT light up and why?
What is a series circuit?


A circuit where current follows only
one _______. Connected _____ to
______.
Diagram:
Series Circuit
• If one light goes ______,
the whole _______ goes out.
• If more ______ are added
all of the bulbs get
________.
Uses:
Automatic doors
Alarms
What is a parallel circuit?
Current follows
_____ than one
______. Connected
in parallel setup.

Parallel Circuit
• If one _______goes out, the others
__________ on.
• If more bulbs are _______ all of
them will still glow at _____
brightness.
Used in:
Homes
Schools
Buildings

Series or parallel? Draw circuit
diagram.
Series or Parallel? Circuit diagram
Series or parallel? Circuit diagram
Series or Parallel? Circuit diagram.
Series or Parallel?
In this setup, is it possible to run the motors without
turning on the bulbs? If not, what would you have to
change?
05/26
Current Electricity Notes
IQ: Going down a plastic slide and getting a static
charge is an example of conversion from:
a. Chemical to mechanical energy
b. Nuclear to electrical energy
c.
Mechanical to light energy
d. Mechanical to electrical energy

Static and Current electricity (8 min)
Conductors


A conductor allows charges/e-s to
flow easily
Some conductors are better than
others
Examples:
Copper
Iron
Insulators

An insulator prevents electric
charges from flowing easily,
Examples:
Rubber
Cork
Wood
Plastic
Charge: A buildup or shortage of electrons.
 Gaining or losing e-s develops a neg. or pos.
charge in an object.
 Charges exert forces (push or pull) on each
other.

Law of Electric Charges
 Like
(same) charges REPEL
 Opposite charges ATTRACT
Current Electricity
Electric Current


Electric Current is the flow of
electrons/charge through a
conductor. SI unit ampere.
There are two types of electric
current:
Alternating Current
Direct Current
Alternating Current (AC)


Changes direction at a regular rate.
Most commonly used type of
electricity because it does not
create as much heat
Examples:
Appliances
Houses
Christmas lights
Direct Current (DC)

Always flows in one direction.
Always flows from negative to positive

Example:
Battery
Creates a lot of heat

Voltage

Electrical pressure (pushes current)
Atoms that are short electrons and
atoms with extra electrons
Unit of measure is the
volt
Measured with a voltmeter
Current

The directed movement of electrons or
the flow. (pushed by voltage)
Unit of measure is the amp or ampere
Measured with an ammeter or amp meter
Resistance

Opposition to current flow (anything
that slows down current), mostly a
load.
Unit of measure is the ohm
Measured with an ohmmeter
Higher resistance would mean ______
(higher, lower) heat produced in a
circuit. Explain.
What is a Battery?


A series of electrochemical cells
Two types:
A wet cell
A dry cell
What is a circuit?
The path an electric current follows
 Consists of four parts:
1.Source:Something to get the power from.
Ex. battery, power line.
2. Load: Something that will use the power
3. Wires: To conduct the electricity

4. Switch: To open or close the circuit,
not essential. Current flows only through a
closed circuit. Brainpop on circuits
Simple Circuit diagram (copy on left page)
Scientists usually draw electric circuits using symbols;
cell
lamp
switch
wires
Diagram of a Circuit (copy)

Copy these circuits on your left
hand side page, talk to your partner
and explain if they will work. Give
reasoning for your answers.

Give some examples of loads that
may be found in your kitchen.
In which of the following circuits will
the bulb NOT light up and why?
5/27
Series and Parallel Circuits
IQ: Which of the following is/are NOT
required to make a circuit work?
a. A source
b. Wires
c. A magnet
d. A load
e. A switch
What is a series circuit?


A circuit where current follows only
one path. Connected back to back.
Diagram:
Series Circuit
• If one light goes out, the
whole circuit goes out.
• If more bulbs are added all
of the bulbs get dimmer.
Uses:
Automatic doors
Alarms
OQ: Christmas lights are connected in
series. What would happen if you
pulled one bulb out? Why?
What is a parallel circuit?
Current follows
more than one
path. Connected
in parallel setup.

Parallel Circuit
• If one light goes out, the others
remain on.
• If more bulbs are added all of
them will still glow at full
brightness.
Used in:
Homes
Schools
Buildings
Brainpop

Series or parallel? Draw circuit
diagram.
Series or Parallel? Circuit diagram
Series or parallel? Circuit diagram
Series or Parallel? Circuit diagram.
In this setup, is it possible to run the motors without
turning on the bulbs? If not, what would you have to
change?
OQ: What role do batteries have in circuits?
A.They are the source of potential energy in
a circuit.
B.They are the source of electrons that
moves through the circuit.
C.They control how hard it is for the
electricity to pass through a circuit.
D.They regulate the electrical current by
storing then releasing charge.

OQ: Which is better to use with
smoke alarms: a series or parallel
circuit and why?
5/23
Circuit Safety
IQ: Draw a circuit diagram with the
following:
One switch controls the whole circuit.
R1 goes out if R2 is broken.
R3 stays on if R1 or R2 is broken.
R3 also has a switch of its own.


Water & broken wires can cause a short circuit




Current skips load
Heats up wire too much
Can cause a fire
Too many plugs in an outlet can cause an
overload
Circuit Safety
1.
Fuses
a) Contains thin strip of metal that current
flows thru
b) If current is too high, metal melts
c) Breaks the circuit, so the e- can’t flow
d) ‘blowing a fuse’
2.
Circuit Breakers
a) A switch
b) Opens when current gets too
high
- strip of wire bends away from
wires in circuit
c) Go to breaker box
& reset
OQ: A charge is a buildup or shortage of
__________in the atoms of a substance.
5/21

Magnetism Notes
IQ: Which two energy resources do not
get their energy from the sun?
Magnetism
Where do magnets come from?

Lodestone is an iron containing mineral that is a
natural magnet. Originally found in Magnesia.





--MAGNET comes from magnetite (a mineral in rocks)
Iron can be made into magnets.
3 things stick to magnets: iron, nickel, cobalt.
Distance decreases magnetic force.
http://www.ndted.org/EducationResources/HighSchool/Magnetism/magneticbehavior.htm
Magnetic Poles


A pole is the area of the magnet
where the magnetic effect is the
strongest.
One pole of the magnet will
always point north- north pole.
The other pole will point southsouth pole.

Like poles repel.

Unlike poles attract.

http://www.ndted.org/EducationResources/HighSchool/Magnetism/twoends.htm
Magnetic
Fields
Magnetic Fields
 Exist
in regions surrounding
magnets.
 Strongest at the poles.
 Exerts a torque on a compass
needle. (Demo)
 Compass needles allow us to map
out magnetic fields.
 Magnetic
field lines flow out
from the N to the S pole.
 They are continuous and never
cross
Magnets have two ends or poles, called north
and south poles. At the poles of a magnet, the
magnetic field lines are closer together.
Unlike poles of magnets
attract each other and like
poles of magnets repel.
Magnetic Domains
What are
magnetic domains?
Magnetic substances like iron, cobalt, and nickel
are composed of small areas where the groups of
atoms are aligned like the poles of a magnet.
These regions are called domains. All of the
domains of a magnetic substance tend to align
themselves in the same direction when placed in
a magnetic field. These domains are typically
composed of billions of atoms.
Making a magnet…


Rubbing a magnetic substance with
a permanent magnet in the same
direction several times can align
all of the domains and the
material will act like a magnet.
http://www.ndted.org/EducationResources/HighSchool/Magnetism/magn
eticdomain.htm
2 types of magnets


Temporary magnets only act as magnets
either in the presence of an electric
current or when near the magnetic field
of another magnet. Ex. electromagnets,
paper clips stuck to a magnet.
Permanent magnets are stronger and
stay magnetized for long periods of
time. Ex. fridge magnets, magnets made
of alnico.
Losing magnetism
Magnets, especially temporary
magnets, will lose their domain
alignment if dropped, struck too
hard, or heated.
The earth is like a giant
magnet!
The nickel iron core of the earth gives the
earth a magnetic field much like a bar
magnet.
Earth’s magnetic field


Maglev Trains
Brainpop

OQ: What would happen if you cut a
bar magnet in half?
Where do magnets come from?




Lodestone is an iron containing mineral that is a
natural magnet. Originally found in Magnesia.
 --MAGNET comes from ________ (a mineral
in rocks)
________ can be made into magnets.
3 things stick to magnets: iron, _______,
_____.
Distance ___________ magnetic force.
Magnetic Poles


A pole is the area of the magnet
where the _________ _______ is
the ___________.
One pole of the magnet will
always point _______- north pole.
The other pole will point south__________.

_____ poles _______.

________ poles _______.
Magnetic Fields
 Exist
in _______ surrounding
magnets.
 _________ at the poles.
 Exerts a torque on a compass
needle. (Demo)
 Compass needles allow us to map
out magnetic fields.
Magnetic Field lines
 Magnetic
_____ lines flow out
from the N to the S pole.
 They are continuous and never
________.
Magnets have two ends or poles, called north
and south poles. At the poles of a magnet, the
magnetic field lines are closer together.
Unlike poles of magnets
attract each other and like
poles of magnets repel.
Magnetic Domains
What are
magnetic domains?
Magnetic substances like iron, cobalt, and nickel
are composed of ____ _______ where the
groups of _______ are __________ like the
poles of a magnet. These regions are called
____________. All of the domains of a
magnetic substance tend to align themselves in
the same __________ when placed in a
magnetic _________. These domains are
typically composed of billions of atoms.
Making a magnet…

Rubbing a magnetic substance
with a _____________
magnet in the same direction
several times can align all of
the ________ and the
material will act like a
________.
2 types of magnets


_________ magnets only act as
magnets either in the presence of an
______ _______ or when near the
magnetic _____ of another ______. Ex.
electromagnets, _______ ______stuck
to a magnet.
___________ magnets are ______ and
stay magnetized for long periods of
time. Ex. ______ magnets, magnets
made of alnico.
Losing magnetism
Magnets, especially temporary
magnets, will _____ their
_______alignment if ______,
______ too hard, or _______.
The earth is like a giant
magnet!
The nickel iron _________ of the earth gives
the earth a magnetic ______much like a
_______magnet.
5/17

Magnetism cont’d
IQ: Find the mistakes in the following
pics/diagrams:
5/20
Electromagnetism, Motors,
Generators notes
IQ: Which of the following is NOT necessary
to produce electricity in a power plant?
a. Mechanical energy
b. Chemical energy
c. Coil/wire
d. Magnets
Electromagnets:
Oersted’s Discovery!
The presence of an electric
current in a wire causes a torque
in a compass nearby.
 A ______ carrying wire
generates a _________ fieldElectromagnetism.


http://www.howstuffworks.com/electromagnet.htm
Electricity & Magnetism

A __________ is a coiled loop of
wire which acts like a bar ________
when ________ is passed through it.
A stronger magnetic field can be made
by using an ______ core/center.
Electromagnets
An electromagnet is a _______ magnet
that can be _______ on and ____.
How to increase ______ in an
electromagnet:
 Increase
_________
 Increase the number of _______ of
wire to the solenoid.
 Wind the coils of a solenoid
___________ together.
 Use __________ ferromagnetic (iron
containing) material for the _______.
Electric Motor



A motor is a device that converts
________ energy into mechanical
energy by making a current carrying
wire spin inside a magnetic field.
Contains an electromagnet.
Uses: ______, washing machines, etc.
What are electric motors?
An electric motor is a device which changes
electrical energy into mechanical energy.
Electric generator


A device that converts __________
energy into electrical energy by using a
wire inside a changing magnetic ______.
Spinning the coiled wire inside the magnetic field makes
electrons move through the wire to light the bulb.
OQ: Which of the following contain/s
a motor? A generator?
a. A battery.
b. A light bulb.
c. A wind turbine.
d. A bicycle.
e. A blender.

OQ: Compare and contrast a motor
and a generator.
Magnetism review

http://www.bbc.co.uk/schools/ks3bi
tesize/science/physics/magnetism_
1.shtml
Diagrams

Source
Resistance

Lamp
Motor

Wire

Switch
OQ: A magnet cannot be used to do
which of the following?
A. Create mechanical energy
B. Create electrical energy
C. Extract aluminum out of a recycling
bin
D. Levitate an object

5/20
Electromagnetism, Motors,
Generators notes
IQ: Which of the following is NOT necessary
to produce electricity in a power plant?
a. Mechanical energy
b. Chemical energy
c. Coil/wire
d. Magnets
Electromagnets:
Oersted’s Discovery!
The presence of an electric
current in a wire causes a
torque in a compass nearby.
 A current carrying wire
generates a magnetic fieldElectromagnetism.


http://www.howstuffworks.com/electromagnet.htm
Electricity & Magnetism

A solenoid is a coiled loop of wire
which acts like a bar magnet
when current is passed through
it.
The direction of the
current determines the
direction of the magnetic
field in a current carrying
wire.
A stronger magnetic field can be made
by using an iron core/center.
Cause
All magnetism is caused
by the movement of
charges.
Electromagnets
An electromagnet is a strong magnet
that can be turned on and off.
How to increase strength in an
electromagnet:
 Increase
current
 Increase the number of loops of wire to
the solenoid.
 Wind the coils of a solenoid closer
together.
 Use stronger ferromagnetic (iron
containing) material for the core.

Brainpop
Electric Motor

A motor is a device that converts
electrical energy into mechanical energy
by making a current carrying wire spin
inside a magnetic field.
Uses: fans, washing machines, etc.

simulation

What are electric motors?
An electric motor is a device which changes
electrical energy into mechanical energy.
How does an electric motor
work?
Go to the next slide 
Simple as that!!
Electric generator

A device that converts mechanical energy
into electrical energy by using a wire
inside a changing magnetic field.

Phet simulation

Brainpop
We have seen how electricity can produce a
magnetic field, but a magnetic field can also
produce electricity! How?
What is electromagnetic induction?
Moving a loop of wire through a magnetic field
produces an electric current. This is
electromagnetic induction.
A generator is used to convert
mechanical energy into electrical energy by
electromagnetic induction.
Carefully study the next diagrams:
OQ: Which of the following contain/s
a motor? A generator?
a. A battery.
b. A light bulb.
c. A wind turbine.
d. A bicycle.
e. A blender.

OQ: Compare and contrast a motor
and a generator.
Magnetism review

http://www.bbc.co.uk/schools/ks3bi
tesize/science/physics/magnetism_
1.shtml
Diagrams

Source
Resistance

Lamp
Motor

Wire

Switch
OQ: A magnet cannot be used to do
which of the following?
A. Create mechanical energy
B. Create electrical energy
C. Extract aluminum out of a recycling
bin
D. Levitate an object

5/29 Current Electricity/Circuits
IQ: Identify the following objects as motor,
generator, solenoid, electromagnet: