Download Record in your notes Examples of Electromagnet Uses

 Complete CRCT Warm-ups for
today.
Distribute the handouts in your team
folder
11.A boat leaves the dock and travels
west reaching a velocity of 6
meters/second after 3 seconds. What
is the acceleration?
A. 0.5 m/s2
B. 2 m/s2
C. 6 m/s2
D. 18 m/s2
12.Which of the following distance vs. time
graphs represent decreasing velocity?
B
Graph _____
13. Which of the following distance vs. time
graphs represent constant velocity?
C
Graph _____
14. Which of the following velocity vs. time
graphs above represents positive acceleration?
D
Graph ______
15. Which of the following velocity vs. time
graphs above represents no acceleration?
F
Graph ______
S8P5. Students will recognize characteristics of
gravity, electricity, and magnetism as major
kinds of forces acting in nature.
b. 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.
Why are some
substances magnetic
and other substances
are not?
Textbook reference: Chapter 19
Key Idea
A magnet is an object
that is surrounded by a
magnetic field and that
has the property of
attracting iron.
The spinning electrons in
every atom produce tiny
magnetic fields. In most
materials the fields of atoms
point in random directions so
the magnetic fields cancel
each other out.
In some materials
the magnetic
fields of electrons
align with one
another. A cluster
of atoms with
magnetic fields
lined up in the
same way is
known as a
magnetic domain.
Record in your notes:
How is a magnet made?
For an object to be magnetic,
most of its domains (tiny
magnetic fields produced by
spinning electrons) must be
aligned in the same
direction.
Before magnetization
After magnetization
Record in your notes:
1. A pole is the area of a magnetic
where the magnetic effect is the
strongest.
Every magnetic has two poles – often
called the north and south pole.
Magnets can produce:
An attractive force (pulling) when unlike
magnetic poles attract
A repulsive force (pushing) when like
magnetic poles repel.
Sounds a lot like the Law of Charges!
Record in your notes:
2. Magnetic force is
caused by a magnet
attracting (pulling)
or repelling
(pushing) other
magnets and some
other materials (e.g.
iron and steel)
Record in your notes:
3. A magnetic field is
area around the
magnet in which
magnetic forces act;
concentrated into a
pattern of lines that
extend from the
magnet’s north pole to its
south pole.
Record in your notes:
4. Magnetic energy
results when an
object is moved a
distance by a
magnetic force.
Record in your notes:
5. Two Kinds of magnets a) Temporary - easy to
magnetize and demagnetize
easily
b) Permanent - hard to
magnetize or demagnetize
Why does a compass point
to the Earth’s North Pole?
Key Idea
A compass points to the
Earth’s North Pole because
the Earth acts like a giant
magnet.
Earth has a north
magnetic pole and a south
magnetic pole.
Earth’s magnetic poles
are not exactly the same
locations as the
geographic poles (axis
where the Earth spins).
A compass can be used to
find directions because its
needle lines up with the
Earth’s magnetic poles.
Consider the following:
What would happen to the
magnetic properties of a
bar magnetic if you cut it
into two pieces?
How can a magnet lose its
magnetic properties?
Losing Magnetic Alignment by:
a) Dropping a magnet or hitting it too hard
b) Putting magnet in opposite field for too
long
c) Increasing the temperature
Key Idea
An electromagnet is a coil of
current-carrying wire that acts
as a magnet that can be turned
on and off.
Solenoid = a current-carrying coil of
wire with many loops.
Record in your notes
When a solenoid is turned on, a magnetic
field is created.
Record in your notes
If a piece of iron or other ferromagnetic material
is wrapped by the coils of wire in a solenoid, a
magnet is created when the current is turned
on.
Record in your notes
The strength of an electromagnet
can be increased by:
1) Increasing the electric current in
the solenoid
2) Increasing the number of coil
loops around the ferromagnetic
material
3) Using a stronger ferromagnetic
material (more iron content)
Examples of Electromagnet Uses:
a) A doorbell or an alarm
Examples of Electromagnet Uses:
a) A doorbell or an alarm
b) Moving junk cars
Examples of Electromagnet Uses:
a) A doorbell or an alarm
b) Moving junk cars
c) Recording data on your
computer
d) Reading the magnetic strip on
the back of a credit card
Examples of Electromagnet Uses:
a) A doorbell or an alarm
b) Moving junk cars
c) Recording data on your
computer
d) Reading the magnetic strip on
the back of a credit card
e) Electric motors
Big Idea about
Electricity and Magnetism
Electromagnetism - interaction
between electricity and magnetism
Big Idea about
Electricity and Magnetism
a. Magnetic forces arise from the
movement of electrical charge.
b. Electrical forces arise from the
movement of a magnet (induced
current)
An index card exit ticket:
1. Why are some substances magnetic?
2. What happens if you cut a magnet in
half?
1. Name three uses of magnets in everyday
life.