Download Magnetism and EM Induction

Magnetism and EM Induction
Conceptual Physics Video Notes
1. What did Hans Christian Oersted discover in 1820?
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2. What is the source of magnetism?
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3. What is the shape of the magnetic field about a current carrying wire?
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4. If the current in the wire is increased what happens to the magnetic field surrounding the
wire?
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5. If the wire is made into a loop or a coil where is the field concentrated?
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6. The piece of iron becomes magnetized by ___________________.
7. In a permanent magnet what charges are moving?
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8. Why is iron a good material for making a magnet? (ferromagnetic)
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9. If you send a “pulse” of current through a copper wire which is positioned in a magnetic
field what will it do? Explain your answer!
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10. What two things could you do to change the direction of force on the wire?
i) ________________________________________________________________________
ii) ________________________________________________________________________
11. What mechanical device uses this principle? How does it work?
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12. What does the “commutator” (split ring) allow to happen in a DC motor? What would happen
if you didn’t have it?
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13. What two things can you change to increase the speed at which a motor will turn?
i)
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ii) ___________________________________________________________________________
14. Which of the above two reasons would account for putting more turns on the motor coil?
Explain!
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15. In 1831 what did Michael Faraday (England) and Joseph Henry (Vermont, USA) discover?
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16. What is Faraday’s Law of Electromagnetic Induction?
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17. How does a generator work?
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18. How does electromagnetic propulsion work? (Aluminum ring in changing magnetic field)
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19. How does a “smart light” work?
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