Download Chapter 8 Test Review Answer Key

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Chapter 8 Test Review
1. What is magnetism?
2. What are the three properties of magnets?
3. What happens when two like poles a brought together? How about two unlike poles?
4. What is an aurora? What are the differences between the northern and southern auroras?
5. What is responsible for causing an object to become a magnet?
6. What is currently causing concerns for scientists regarding Earth’s magnetic field?
7. Can a magnetic pole be isolated? (Can you only have a north pole on a magnet?)
8. How does electricity affect magnetism?
9. What is the right hand rule and how do you use it?
10. What is an electromagnet?
11. What are the properties of an electromagnet?
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12. How does current affect the magnetic field of an electromagnet?
13. Explain how a speaker works due to an electromagnet and a permanent magnet.
14. What causes an electric motor to spin?
15. What is a galvanometer?
16. What is a magnetic field?
17. What is a magnetic domain?
18. What is a magnetic pole?
19. What is a solenoid?
20. What is an electric motor?
21. What is a generator?
22. What is a turbine?
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23. What do AC and DC stand for? What is the difference between the two?
24. What is a transformer?
25. What is the difference between a step-up transformer and a step-down transformer?
26. What are some examples of electric motors?
27. How do cars use galvanometers?
28. Explain in detail how a galvanometer can make a gage reading, such as a fuel gage, go up and
down.
29. You can get up to 11 bonus points for this test:
a. If you do the vocabulary for this chapter and turn it in with the test you can get 5 bonus
points. There are 14 words for this chapter.
b. There will be three bonus math problems based on the math we already learned. These
will be worth 2 points each for a total of 6 possible points. The equations will be on the
board, all you have to do is know how to use them.
*If you need help I am available before school, after school, and during MUST on Fridays. There is a
signup sheet in my room on the bulletin board that you can use.
Name: ____________________________
Chapter 8 Test Review Answer Key
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The properties and interactions of magnets
They have magnetic fields, they have magnetic forces, and they have poles (a north and a south)
Like pole repel, unlike poles attract
Tiny little mini magnets known as magnetic domains
An aurora is the visible affect of space radiation striking Earth’s magnetic field. In the north it is
called the aurora borealis and is usually blue-green in color. In the south it is called the aurora
australis and is usually red-orange in color.
The magnetic field is weakening, and at the current rate will disappear in about 2,000 years.
No because a magnet is made up of magnetic domains every time you break a magnet the newly
exposed ends will become the new pole.
Electricity can induce, or cause, a magnetic field to occur.
The right hand rule is used to say what direction the magnetic field is going. Your thumb of your
right hand points in the direction of the electric current, and your finger curl into a c-shape in
the direction of the magnetic field.
A temporary magnet made by wrapping a wire coil, carrying a current, around an iron core
It is temporary (only works as long as electricity is flowing), it’s strength can be manipulated, it
has two poles (north and south), attracts other magnetic material, and when there is a current
can cause the magnet to want to move towards or away from another magnet, this movement
is mechanical energy which can be changed into work (can cause things to move)
Depending on the direction of electric current it will make the magnetic field move either
clockwise or counterclockwise
A speaker has a coil of wire that is a temporary magnet, surrounded by a permanent magnet.
When the temporary magnet is turned on it tries to move away from the permanent magnet.
This causes a force to be produced. This force is then translated into mechanical energy that
causes the cone of the speaker to vibrate. These vibrations create sound waves which we then
interpret as sound.
An electromagnet spins because it is near a permanent magnet that causes the spinning to
occur as the electromagnet is trying to get away from the permanent magnet since like poles
repel.
A devise that uses an electromagnet to measure electric current
Surrounds a magnet and exerts a force on other magnets and objects made of magnetic
materials
Region on a magnet where the magnetic force exerted by a magnet is strongest; like poles repel
unlike poles attract
Group of atoms in a magnetic material with the magnetic poles of the atoms pointing in the
same direction
A wire wrapped into a cylindrical coil
Device that converts electrical energy to mechanical energy by using the magnetic forces
between an electromagnet and a permanent magnet to make a shaft rotate
Device that uses electromagnetic induction to convert mechanical energy to electrical energy
Name: ____________________________
22. Large wheel that rotates when pushed by steam, wind, or water and provides mechanical
energy to a generator
23. AC= alternating current, which is when the current switches directions in a regular pattern.
DC=direct current, which is when current can only flow in one direction
24. Device that uses electromagnetic induction to increase or decrease the voltage of an alternating
current
25. A step-up transformer has more loops on the secondary coil of a transformer than the primary
coil. A step-down transformer has fewer loops on the secondary coil than the primary coil.
26. Car, fan, blender, washing machine, dryer, hairdryer, computer, refrigerator, ect.
27. They are used for gauges such as the fuel gage and the engine temperature gauge.
28. In the fuel tank there is a float. This float has a magnet in it and a wire that can conduct
electricity. At the top of the fuel tank there is another magnet. When the tank is full the two
magnets are closer together, generating a strong magnetic force that causes the gauge to have
enough electricity to make it read full. As the gas level lowers the magnets get further away
making so they produce less electricity so the gauge starts to lower.