1. Faraday
Generators/
Motors
Induced
Current
Lenz’s Law/
Changing B
Transformers
1pt
1 pt
1 pt
1pt
1 pt
2 pt
2 pt
2pt
2pt
2 pt
3 pt
3 pt
3 pt
3 pt
3 pt
4 pt
4 pt
4pt
4 pt
4pt
5pt
5 pt
5 pt
5 pt
5 pt

2. In 1822, Michael Faraday wrote a goal in his notebook:

3. “Convert Magnetism into Electricity”

4. A magnetic field can induce a current.

5. Electromagnetic Induction

6. The conductor, which is often a piece of wire, must be ________ to the magnetic lines of force

7. Perpendicular

8. The direction of the induced current is dependent on the relative motion of the coil with respect to the magnet.

9. The Generator Effect

10. State the 4th RHR… one used for Faraday’s law.

11. -Outstretched fingers are magnetic field
-Extended thumb is direction wire moves
-Palm shows direction of current flow

12. Changes mechanical energy into electrical energy.

13. Generator

14. Coil of wire around a soft iron core to concentrate magnetic force

15. Armature

16. Changes electrical energy into mechanical energy

17. Motor

18. When a generator is connected in a closed circuit; the current flow is proportional to the _______

19. Electromotive Force (EMF)

20. 0.707 times the maximum voltage

21. Effective Voltage

22. Even though it is called a force, it is a potential difference and is measured in volts.

23. Electromotive Force (EMF)

24. An induced EMF that resists the applied EMF

25. Back EMF

26. The formula for calculating EMF, also state what the variables are.

27. L is the length of the conductor
vBL
v is the velocity
B is the field strength
L is the length of the conductor

28. A permanent horseshoe magnet is mounted so that the magnetic field lines are vertical. If a student passes a straight wire between the poles and pulls it toward herself, the current flow through the wire is from left to right. Which is the N – pole of the magnet?

29. The top

30. 3 Ways to increase EMF:

31. Increase the velocity of the wire Increase the length of the wire
Increase the magnetic field strength

32. We will use our ____ RHR when dealing with Lenz’s law

33. Second

34. An induced current always flows in such a direction as to oppose the motion that induced it.

35. Lenz’s Law

36. ________ currents are generated to stop the motion of the metal arm of a sensitive scale.

37. Eddy

38. If a mechanical load is placed on the motor, slowing it down, the back EMF is ______.

39. Reduced

40. The N-pole of a magnet is moved toward the right end of a coil
The N-pole of a magnet is moved toward the right end of a coil. The direction of the induced current is?

41. Counter clockwise

42. The varying magnetic flux is carried through the core to the secondary coil which induces a varying EMF in the secondary coil. This is called ______
________

43. Mutual Inductance

44. A step-up transformer increases voltage – the current in the primary circuit is ______ than that in the secondary.

45. Greater

46. Upon what does the ratio of the EMF in the primary of a transformer to the EMF in the secondary of the transformer depend?

47. The ratio of number of turns of wire in the primary to the number of turns of wire in the secondary.

48. Transformer Formula

49. Vs/Ns = Vp/Np Or
Ip/Is = Vs/Ns = Vp/Np

50. In a transformer, current is inversely proportional to ______

51. Voltage

52. The power produced in the primary coil is ______ to the power produced in the secondary coil.

53. Equal