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of 78 available terms

### 72 Matching questions

1. Real transformers
2. first coil called primary
3. maximum emf
4. wire&wire
5. electromagnetic waves
6. ω
7. decrease
8. Step-up transformer
9. 230 000V
10. 0 emf
12. James Clerk Maxwell
13. transverse waves
14. mechanical energy
15. AC can be converted to DC
16. Second coil called secondary
17. Heinrich Hertz
18. right
19. size & rotating
20. same
21. motor
22. 3rd
23. CHANGE
24. magnetic field
25. waves
26. volt (V)
27. back emf
28. frequency
29. lens law
30. Back emf
31. Electromagnetic induction
32. increase
33. electromagnetic in nature
34. M
35. Step-down transformer
36. emf from one loop
37. perpendicular
38. Lenz's law
39. 12V
40. particles
41. bar magnet
42. Equation for single loop
43. single force
44. emf for generator (maximum)
45. -rotate a wire
-drag a wire through magnetic field
-move a magnetic field across a wire
47. emf
48. The Ignition coil
49. Mutual inductance
50. wave-particle duality of light
51. inverse square law
52. electrons
53. accelerating charges
55. emf & current
56. charged particular
57. reduce
58. opposite
59. Ohm's Law
60. induced field
61. AC current
62. permanent magnet
63. equation for multiple loops
64. photon
65. number
66. transformers
67. orientation
68. potential difference
69. transformer equation
70. parallel
71. energy
72. -speed of wire or magnetic field motion
-length of wire in the field
-strength of magnetic field
1. a ___performed experiments that generated and detected EM waves and confirmed Maxwell's predictions.
2. b The current induced in the wire by moving through a magnetic field will generate its own _______
3. c Notion that EM waves behave like particles is called the____
4. d __ depends on the shape of the coils and how they are orientated to each other
5. e emf unit is the
6. f Magnitude of emf depends on (3):
7. g when the armature is parallel to the magnetic field in a generator, you get ____
8. h three ways to induce current
9. i When you have multiple loops, you multiple the number of loops (N) by the ____
10. j The increase in emf means a____ in current
11. k A particle of light is called a____ - carries energy, but has no mass
12. l increases the emf, N2 is greater than N1
13. m As the coil moves out of the magnetic field the induced field is in the_____ direction as the original and they attract each other
14. n As the loop rotates from one arm being up to the other being up, the current flow will change direction - producing ____
15. o Energy transported by EM waves is called ____
16. p The induced field does not oppose applied field, but the____ in the applied field
17. q An decrease in emf means an____ in current
18. r If the applied field changes, the _____ helps to keep it constant
19. s Changing the____ of coils in the secondary coil can change the induced emf in the secondary coil - used in making transformers
20. t decreases the emf, N2is less than N1
21. u _____ are only 90-99% efficient - power is lost due to small currents induced by changing magnetic field and resistance in the wires
22. v As a motor turns more quickly, the net emf and net current in the coil___
23. w Predicts the magnitude of induced emf
24. x A device that increases or decreases the emf of alternating current
25. y Current can also be generated in a magnetic field by changing the_____ of the loop in the magnetic field
26. z ∆V2/∆V1 = N2/N1
27. aa when the armature is perpendicular to the magnetic field in a generator, you get____
28. ab motion of _____ through a wave makes it move
29. ac ____created a set of equations that explain the relationship between electric and magnetic fields
30. ad current in this coil magnetizes the iron core
31. ae Induced current is greatest if the wire and magnetic field are_____ to each other
32. af The magnetic field force pushes the___ through the wire
33. ag Current is supplied to loops and that magnetic field repels ______ and causes the loops to rotate
34. ah emf = NAβω
35. ai The induced magnetic field is similar to a _____- and creates a force that repels the original magnetic field
36. aj ____ is the ability of one circuit to induce emf in a nearby circuit in the presence of a changing magnetic field
37. ak electromagnetic waves are ___
38. al Oscillating Electric and Magnetic waves - at___ angles to each other
39. am Some high energy EM waves will behave like____
40. an current runs through the 2nd coil because it is wrapped around magnetized iron
41. ao Electromagnetic waves transfer____ - stored in the oscillations of the electric and magnetic fields
42. ap is the angular speed of rotation of the loop (2πf)
43. aq Because AC current changes direction, the____ and____ in an AC circuit is not constant
44. ar Car batteries provide a constant DC emf of ___
45. as A generator produces changing____, because of its constant rotating
46. at convert electrical energy to mechanical energy
47. au tells the direction of the induced emf
48. av Electric and magnetic forces are aspects of a ____ - called electromagnetic force
49. aw The motor's magnetic field generates its own emf called ___
50. ax Low-energy photons behave more like ___
51. ay Electromagnetic force obeys the ____ - as the two objects move further apart the force between them weakens
52. az The____ of rotation of the loop in a generator will determine how often the current changes direction -> f = 60Hz in US
53. ba if the angle is zero the wire is____ to the magnetic field
54. bb Use the ___ right hand rule to figure out the direction of current flow in the wire
55. bc Oscillating electric and magnetic fields create
56. bd In the US, power companies step-up emf to about ____
57. be You can use ____ to find resistance
58. bf producing current in a wire by placing it in a changing magnetic field
59. bg The _____ supplied to the motor equals the applied emf minus the back emf, this also reduces current
60. bh ____ in the engine is a transformer that increases this emf to a great enough value to cause a spark between the gaps of a spark plug
61. bi N∆ϕM/∆t
62. bj Either the ____ can move in the magnetic field or the field can move around the ____ - one or the other must move to induce current.
63. bk Maxwell predicted that light was ___-
64. bl add rings (slip rings) and brushes to the end of the loops, the moving rings counter the changing current and create direct current for a circuit
65. bm ____ increases as the magnitude of the magnetic field changes at a higher rate
66. bn "The magnetic field of an induced current is in a direction to produce a field that oppose the change causing it"
67. bo Most power plants use a source of _____ to turn a turbine in a magnetic field to generate current.
68. bp Changing the ___ of the loops of wire or _____ the loop in the magnetic field will change the amount of induced current
69. bq who first demonstrated the principle of electromagnetic induction
70. br emf = -∆ϕM/∆t
71. bs As the magnetic field approaches the wire, the wire's magnetic field is in the____ direction of the increasing magnetic field
72. bt All EM waves are produced by ____ - a charge moves up/down through the wave at a certain frequency