Question

1. what does a magnetic field look like?

a. a series of white, dotted lines.
b. its invisible.
c. a clear piece of plastic or glass.
d. a shimmering area in the air.

1. how are the magnetic domains of a magnet different from the domains of an ordinary piece of metal?

a. in a magnet, the domains all point in the same direction; in an ordinary piece of metal, theyre all jumbled up.
b. in a magnet, the domains all point toward the north pole; in an ordinary piece of metal, they all point to the south pole.
c. in a magnet, the domains are very strong; in an ordinary piece of metal, theyre very weak.
d. a magnet contains magnetic domains; an ordinary piece of metal does not

1. what can you infer about magnetic domains from the fact that they are arrangements of atoms?

a. the individual domains are extremely small.
b. the individual domains are extremely large.
c. the individual domains attract one another.
d. the individual domains repel one another.

1. why are the magnetic domains of this paperclip lined up?

a. because the paperclip has acquired a static charge.
b. because a paperclip is a type of electromagnet.
c. because paperclips are permanent magnets.
d. because the paperclip has been exposed to a magnetic field.

1. which of the following metals can be magnetized?

a. lead
b. iron
c. copper
d. silver

1. how can you create a magnetic field?

a. by stringing many magnets together
b. by plugging a refrigerator magnet into an electric socket
c. by rubbing a piece of glass against a piece of wool
d. by running a current through a wire

1. which of the following statements is true?

a. a compass is affected by the earths magnetic field.
b. an objects magnetic field gets weaker as you move closer to it.
c. once a piece of metal becomes magnetized, it stays magnetized.
d. the earths magnetic north pole is located at the geographical north pole.

1. where might you find an electromagnet?

a. in a fluorescent light bulb
b. hanging on your refrigerator door
c. in an electric motor
d. in pieces of rock called magnetite

1. what can you conclude about electricity and magnetism from the information presented in the movie?

a. they have nothing to do with one another.
b. they cannot be controlled.
c. they are related phenomena.
d. they have no practical applications.

1. if you have an electromagnet, how can you make its magnetic field stronger?

a. increase the size of the magnetic domains
b. increase the strength of the electrical current
c. increase the length of the wire
d. increase the distance between the north and south poles

Explanation:

1. A magnetic field is invisible, so the answer is b.
2. In a magnet, magnetic domains are aligned in the same direction, while in an ordinary metal they are randomly oriented. So the answer is a.
3. Since magnetic domains are arrangements of atoms, they are extremely small. So the answer is a.
4. A paper - clip's magnetic domains line up when exposed to a magnetic field. So the answer is d.
5. Iron is a ferromagnetic material and can be magnetized. So the answer is b.
6. A magnetic field can be created by running a current through a wire (electromagnetism principle). So the answer is d.
7. A compass is affected by the Earth's magnetic field. So the answer is a.
8. Electromagnets are used in electric motors. So the answer is c.
9. Electricity and magnetism are related phenomena (electromagnetism). So the answer is c.
10. For an electromagnet, increasing the strength of the electrical current increases the strength of the magnetic field. So the answer is b.

Answer:

1. b. It's invisible.
2. a. In a magnet, the domains all point in the same direction; in an ordinary piece of metal, they're all jumbled up.
3. a. The individual domains are extremely small.
4. d. Because the paperclip has been exposed to a magnetic field.
5. b. Iron
6. d. By running a current through a wire
7. a. A compass is affected by the earth's magnetic field.
8. c. In an electric motor
9. c. They are related phenomena.
10. b. Increase the strength of the electrical current