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20 Cards in this Set
- Front
- Back
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a magnetic field moving over a conductor can ___ an electrical current in the conductor |
"induce" |
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electromagnetic induction was first demonstrated by who..when? |
Michael Faraday; 1821 |
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three ways to create motion between the conductor and the magnetic field |
1. move the conductor through a stationary magnetic field 2. move the lines of force over the conductor without changing the field strength 3. vary the magnetic field strength of a stationary magnet across a stationary conductor |
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why is motion created by varying the magnetic field strength of a stationary magnet across a stationary conductor? |
bc as field strength changes, the lines of force expand and contract |
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electromotive force- |
potential difference induced in the conductor |
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when is electromotive force created? |
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what are the units for emf? |
volts |
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flux linkage- |
interaction of one line of force and one loop of conductor |
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what is the magnitude of the induced emf determined by? |
number of flux linkages per second |
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the four factors that influence the magnitude of induced emf is known as what? |
faraday's law or the first law of electromagnetics |
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what are the four factors that influence the magnitude of induced emf? |
1. the strength of the magnetic field 2. the speed of the motion between the conductor and the flux line 3. the angle between the flux lines and the conductor 4. the number of turns or coils in the conductor |
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the stronger the magnetic field, the closer/further the flux lines are? |
closer |
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the more flux lines that are cut (flux linkages) per second, the more/less the induced emf? |
more |
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the faster the conductor is traveling, the more/less flux linkages per second? therefore the more/less induced emf? |
more; more |
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the closer to 90*, the more/less flux linkages per second? therefore the more/less induced emf? |
more;more |
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the greater/less number of turns, the more the flux linkages per second? therefore the more the induced emf. |
greater |
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when a conductor moves through a magnetic field a ___ is induced |
current |
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when we know the direction of the __ __ and the direction of the __ , we can determine the direction of the current by using what? |
magnetic field; motion of the conductor; fleming's right hand generator rule |
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what hand is used for electrons and which for current? |
current= right electrons=left |
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pointer finger = thumb= middle finger = |
field direction motion direction direction of current |
