1. Upcoming Deadlines
USA Test Prep Activities completed by Tuesday, March 10
Summative Assessment over Electricity and Magnetism on Tuesday, March 10

2. Science Standard
SPS10. Students will investigate the properties of electricity and magnetism.
Investigate applications of magnetism and/or its relationship to the movement of electrical charge as it relates to
electromagnets, simple motors, and
permanent magnets     2

3. Why are some substances magnetic and other substances are not?
Essential Question
Why are some substances magnetic and other substances are not? 3

4. Key Idea
A magnet is an object that is surrounded by a magnetic field and that has the property of attracting iron.

5. The spinning electrons in every atom produce tiny magnetic fields
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.

6. 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.

7. 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.

8. Before magnetization
After magnetization

9. 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.

11. 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!

12. Magnetic force is caused by a magnet attracting (pulling) or repelling (pushing) other magnets and some other materials (e.g. iron and steel)

15. 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.

17. Magnetic energy results when an object is moved a distance by a magnetic force.

18. Two Kinds of magnets -
a) Temporary - easy to magnetize and demagnetize easily
b) Permanent - hard to magnetize or demagnetize

19. Why does a compass point to the Earth’s North Pole?

20. Why does a compass point to the Earth’s North Pole?
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.

22. A compass can be used to find directions because its needle lines up with the Earth’s magnetic poles.

24. Consider the following:
What would happen to the magnetic properties of a bar magnetic if you cut it into two pieces?

25. You would have two magnets, each with its own north and south pole.

26. How can a magnet lose its magnetic properties?
a) Dropping a magnet or hitting it too hard
b) Putting magnet in opposite field for too long
c) Increasing the temperature

27. Key Idea
An electromagnet is a coil of current-carrying wire that acts as a magnet that can be turned on and off.

28. Solenoid = a current-carrying coil of wire with many loops.

29. When a solenoid is turned on, a magnetic field is created.

30. 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.

31. The strength of an electromagnet can be increased by:
Increasing the electric current in the solenoid
Increasing the number of coil loops around the ferromagnetic material
Using a stronger ferromagnetic material (more iron content)

33. Examples of Electromagnet Uses:
A doorbell or an alarm

35. Examples of Electromagnet Uses:
A doorbell or an alarm
Moving junk cars

37. Examples of Electromagnet Uses:
A doorbell or an alarm
Moving junk cars
Recording data on your computer
Reading the magnetic strip on the back of a credit card

39. Examples of Electromagnet Uses:
A doorbell or an alarm
Moving junk cars
Recording data on your computer
Reading the magnetic strip on the back of a credit card
Electric motors

40. Electricity and Magnetism
Big Idea about
Electricity and Magnetism
Electromagnetism - interaction between electricity and magnetism

41. 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)

42. Motors
An electric motor is a device that changes electrical energy into mechanical energy.
All electric motors have an armature—a loop or coil of wire that can rotate. The armature is mounted between the poles of a permanent magnet or electromagnet.

44. Generators
A generator is a device that uses electromagnetic induction to change mechanical energy into electrical energy.
An electric current is made when a magnet moves in a coil of wire or when a wire moves between the poles of a magnet (electromagnetic induction).

46. Take Aways Why are some substances magnetic?
What happens if you cut a magnet in half?
Name three uses of magnets in everyday life.