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40 Cards in this Set
- Front
- Back
What is any material that attracts iron or material containing iron?
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magnet
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What is the force which can cause attraction or repelling by moving charges?
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magnetic force
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What is one of 2 points, such as the ends of a magnet, that have opposing magnet in which magnetic force acts?
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magnetic pole
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What is a region around a magnet in which magnetic force acts?
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magnetic fiel
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What is the area of activity; area or magnetic field of an atom where its electic charges exist?
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domain
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How can materials become magnetized?
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-when domains line up
-rub iron in 1 direction with pole -being under the influence of a magnetic field |
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Describe some ways a magnet can become demagnetized.
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-dropping it
-increasing the temp. -hitting it too hard -putting it under the influence of a stronger magnet |
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How does loss of magnetism occur?
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can occur cuz domains move and become random (they aren't lined up anymore)
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What do scientists think is the cause of the northern lights?
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charged particles from the sun hit our atmosphere, gain energy, and give off light
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What magnet is difficult to magnetize and keeps its magnetic property longer?
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permanent
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What magnet is easy to magnetize and looses magnetic property easily?
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temporary
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What do you end up with if you cut a bar magnet in half?
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2 magnets
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In what direction does the end of a compass needle always point?
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magnetic South and geographic North
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What is the interaction between electricity and magnetism?
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electromagnetism
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What is a coil that has a soft iron core and that acts as a magnet when an electric current is in the coil?
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electromagnet
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What is a coil of wire with an electric current in it?
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solenoid
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What is a device that converts electrical energy into mechanical energy?
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electric motor
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How can the strength of an electromagnet be increased?
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increase # of coils per meter in the solenoid
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What makes the armature in an electric motor rotate?
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magnet repels and attracts
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What reverses the direction of the electric current in a wire in the armature?
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commutator
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What measures or detects current?
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galvometer
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What electric current is made by a changing magnetic field?
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electromagnetic induction
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What uses electromagnet induction to change mechanical energy into electrical energy?
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electric generator
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How does a generator produce an electric current?
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coils turn in a magnetic field or magnet turns around coils
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How can the current produced by a generator be increased?
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increase # of coils or the speed at which they are turned
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What increases or decreases the voltage of AC?
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transformer
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What increases voltage and decreases current?
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step up transformer
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What decreases voltage and increases current?
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step down transformer
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In which transformer does the primary have fewer loops than the secondary?
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step up transformer
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In which transformer does the primary have more loops than the secondary?
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step down transformer
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How can an electric current be produced in a wire using magnetism?
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by moving the wires in a magnetic field or moving magnetic field around the wire
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What charges continually shift from flowing in one direction to flowing in the reverse direction?
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alternating current
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What charges always flow in the same direction?
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direct current
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An ___________ changes electrical energy into mechanical energy.
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electric motor
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A __________ changes mechanical energy into electrical energy.
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generator
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What are magnets made of metal with strong magnetic properties? What metals are in it?
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ferromagnet; magnetite, iron, nickel, and cobalt
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What is the cause of magnetism?
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-electrons are moving in atoms, this creates a magnetic field, when domains line up
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What is a coil of wire in an electric motor and is inside of a permanent magnet or electromagnet?
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armature
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Why is electricity sent through wires at high voltage?
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to decrease power loss
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What does electricity normally go through before it comes to the houses?
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2 step down transformers
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