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10 Cards in this Set
- Front
- Back
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magnetic materials
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materials that are attracted to a magnet (998)
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magnetic dipole
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each permanent magnet has two poles: north and south poles
cutting a permanent magnet into two yields two weaker but still complete magnets (998) |
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magnetic monopole
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an isolated magnetic pole, i.e. a north pole in the absence of a south pole
this has never been observed (998) |
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The Earth is a giant magnet.
Which is the geographic north/south pole? |
The Earth's magnetic poles come from currents in its molten core.
The Earth's geographic north pole attracts the north pole of a compass. The Earth's geographic south pole attracts the south pole of a compass. The Earth's geographic north pole is its south magnetic pole. The Earth's geographic south pole is its north magnetic pole. (998) |
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Who discovered the magnetic field, and how was it discovered?
What did the discovery of magnetism imply? |
The Danish scientist, Hans Christian Oersted discovered the magnetic field during a classroom lecture demonstration in 1819.
The discovery of magnetism implied that magnetism was caused by an electric current. (998) |
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What is the effect of a current on a compass?
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A strong current causes the compass to pivot until it is tangent to a circle around the wire. (999)
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Properties of a magnetic field, B
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1. It is at all spaces surrounding a current carrying wire.
2. It is a vector at each point with a magnitude (magnetic field strength) and a direction. 3. It exerts forces on magnetic poles. The forces are parallel to the north and south pole. However, the north pole points in the same direction as the magnetic field. (999) |
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How do magnetic field lines differ from electric field lines?
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Magnetic field lines form loops around current-carrying wire. Electric field lines start on positive charges and stop on negative charges. (1000)
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What is the SI unit for a magnetic field strength?
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tesla, T
1 tesla = 1 T = 1 N/A*m (This is based on the magnetic force of a current-carrying wire.) (1001) |
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What is the value of the magnetic field, B, along the line of motion?
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B = 0 because the angle, theta = 180 or 0
(1002) |
