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51 Cards in this Set
- Front
- Back
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What is wire carrying a current wrapped around a metal core?
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An electromagnet
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Who was the 1st person who realized that an electric current produces a magnetic field?
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Hans Oersted
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What is a device that converts electric energy into mechanical energy?
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A motor
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A device that converts mechanical energy into electric energy is called a what?
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A generator
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A device that increases or decreases voltage is called a what?
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A transformer
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A scientist who discovered that an electric current can be induced by moving a wire through a magnetic field was?
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Michael Faraday
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In a step-up transformer, r there more loops on the secondary coil or the primary coil?
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Seconday has more
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How can an eltromagnet be weakened?
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By decreasing the current
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What r 2 parts of a motor?
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Brushes and commutators
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Solenoid
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A long coil of wire w/ many loops
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What is the relationship b/t electricity & magnetism known as?
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Electromagnetism
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The magnetic field lines produced by a current in a straight wire are in the shape of what?
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circles
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The most efficient electromagnet uses a core of what?
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iron
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the rotating electromagnet in an electric motor is called the what?
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an armature
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A motor can be made to run off direct current by using a what?
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A commutator
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Does a fluorescent light have a step-up transformer or a step-down transformer?
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Step-up
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What type of transformer does a radio have?
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step-down
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The alternating current used in the US has a frequency of what?
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60 hertz
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Most of the electricity used in ppl's homes is produced by?
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generators
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What is a current that travels in only one direction called?
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A direct current
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What is a current that travels back and forth called?
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Alternating current
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When a wire carrying a current is twisted into loops, what happens to its magnetic field?
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Its strength is increased
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Electromagnets
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strong temporary magnets
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Electric current is supplied to the commutator of a motor through the what?
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brushes
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what is a galvanometer found in?
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voltmeters and ammeter
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An induced current is produced by what?
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A changing magnetic field
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What do modern generators produce?
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An alternating current
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The mechanical energy neede to run generators is produced by what?
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the burning of oil
The burning of coal nuclear fusion |
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What does a solenoid act like a magnet?
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When a current passes through it
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What can be used to deflect a compass needle?
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An electric current
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What will happen to an electric current exposed to a changing magnetic field/
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It will be induced in a circuit
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When a wire carrying a current is twisted into loops, what happens to its magnetic field?
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Its strength is increased
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Electromagnets
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strong temporary magnets
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Electric current is supplied to the commutator of a motor through the what?
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brushes
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what is a galvanometer found in?
|
voltmeters and ammeter
|
|
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An induced current is produced by what?
|
A changing magnetic field
|
|
|
What do modern generators produce?
|
An alternating current
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|
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The mechanical energy neede to run generators is produced by what?
|
the burning of oil
The burning of coal nuclear fusion |
|
|
What does a solenoid act like a magnet?
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When a current passes through it
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|
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What can be used to deflect a compass needle?
|
An electric current
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What will happen to an electric current exposed to a changing magnetic field/
|
It will be induced in a circuit
|
|
|
When a wire carrying a current is twisted into loops, what happens to its magnetic field?
|
Its strength is increased
|
|
|
Electromagnets
|
strong temporary magnets
|
|
|
Electric current is supplied to the commutator of a motor through the what?
|
brushes
|
|
|
what is a galvanometer found in?
|
voltmeters and ammeter
|
|
|
An induced current is produced by what?
|
A changing magnetic field
|
|
|
What do modern generators produce?
|
An alternating current
|
|
|
The mechanical energy neede to run generators is produced by what?
|
the burning of oil
The burning of coal nuclear fusion |
|
|
What does a solenoid act like a magnet?
|
When a current passes through it
|
|
|
What can be used to deflect a compass needle?
|
An electric current
|
|
|
What will happen to an electric current exposed to a changing magnetic field/
|
It will be induced in a circuit
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