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| explain the earth's magnetic field |
the magnetic south is at the north pole, and the magnetic north is at the south pole. compasses will always point to the magnetic south pole. |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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magnetically (1) materials gain and lose magnetism easily.
magnetically (20 materials do not gain or lose magnetism easily |
1. soft
2. hard |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| how do you weaken a magnet? |
1. heat the material
2. hammer the material |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| how do you make temporary permanent magnets? |
1. rub the material with a permanent magnet
2. place the material near a very strong magnet |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| magnets that sustain their magnetism all the time |
permanent magnets |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| what is magnetism caused by? |
moving electric charges |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a device that can change one alternating current voltage to a different alternating-current voltage |
transformer |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| how is water used as electrical energy? |
kinetic energy is taken from the water to turn the turbine. Electromagnetic inductino turns it to electric energy |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| an electric current that changes directino at regular intervals |
alternating current (AC) |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a device that uses electromagnetic induction to convert mechanical energy to electrical energy |
generator |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| the production of a current in a conducting circuit by a change in the strength, position, or orientation of an external magnetic field |
electromagnetic induction |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| how does an electric motor work? |
like a galvanometer, but it has a coil attached to a shaft and keeps spinning. A device called a commutator, connected by brushes, make the current change direction every time the flat coil makes a half revolution. If the current didn't keep changing, the loop would come to a rest due to friction. |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a device that converts electrical energy to mechanical energy |
electric motor |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| how does a galvanometer work? |
it consists of an electromagnet that can spin between the poles of a permanent magnet, and the two magnetic fields will interact. the resulting forces will turn the core and move the needle. |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| an instrument that measures the amount of current in a circuit |
galvanometer |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction |
domain |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a strong magnet created when an iron core is inserted into the center of a current-carrying solenoid |
electromagnet |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a long, wound coil of insulated wire |
solenoid |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| a region where a magnetic force can be detected |
magnetic field |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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| an area of a magnet where the magnetic force appears to be the strongest |
magentic pole |
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chunsah Tue, 04 Mar 2008 02:51:37 GMT |
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