1. Magnetism Science Chap 7 1 3 2 4 5 7 6 8 910 1112 1314 1 3 2 4 5 7 6 8 910 1112 1314

2. Use the control buttons on the right to move from item to item in any order. Use the control buttons on top to flip card or move through the cards one at a time. flip Gold: Questions Orange: Answers First Previous Flip Next Last Help Page Return

3. Q1 flip 1 3 2 4 5 7 6 8 910 1112 1314 Name ways to make an electric motor more powerful by making its magnet stronger?

4. 1 3 2 4 5 7 6 8 910 1112 1314 flip A1 These are a few ways to make an electric motor more powerful: Use a larger current flowing through the coil. Increase the number of turns of wire around the coil. Use a soft-iron core in the middle of the coil. Use stronger magnets, such as electromagnets either side of the coil.

5. flip 1 3 2 4 5 7 6 8 910 1112 1314 2 Explain how the acronym: M y F ine C lothes Can be used to remember the left-hand rule that is used with motors?

6. 1 3 2 4 5 7 6 8 910 1112 1314 flip 2 M y = Thu m b to remember M otion of wire F ine = F irst finger to remember F ield C lothes = S econd finger to remember C urrent Place fingers at 90 degrees from each other.

7. flip 1 3 2 4 5 7 6 8 910 1112 1314 3 Apply the left-hand rule to the following drawing. Where does your thumb, first and second fingers point to?

8. 1 3 2 4 5 7 6 8 910 1112 1314 flip 3 C urrent = Se c ond finger points in direction of current F ield = F irst finger points in direction of field (North to South) M otion = Thu m b points up so wire moves upwards.

9. flip 1 3 2 4 5 7 6 8 910 1112 1314 4 When a current flows through a wire it produces a: (finish the sentence)

10. 1 3 2 4 5 7 6 8 910 1112 1314 flip 4 When a current flows through a wire it produces a magnetic field. Red wire is positive so it is the north pole. Do you notice that the compasses point away from the north?

11. flip 1 3 2 4 5 7 6 8 910 1112 1314 5 The simplest type of electromagnet is a coiled piece of wire. A coil forming the shape of a straight tube (similar to a corkscrew). What is this type of electromagnet called?

12. 1 3 2 4 5 7 6 8 910 1112 1314 flip 5 It is called a solenoid. The current of negative flows to the positive. The north pole will be positive.

13. flip 1 3 2 4 5 7 6 8 910 1112 1314 6 In the two following diagrams of cobalt. Explain which will be magnetic and what term is used to described the little rods that are part of atoms.

14. 1 3 2 4 5 7 6 8 910 1112 1314 flip 6 In the case of the domains that are not organized, the cobalt will not be magnetic. In the case of the domains that are organized, the cobalt will be magnetic. They become organized if a magnet comes close to the piece of cobalt. A domain is the ordering of electron spins. When they are organized in the same spin then they create magnetism. unorganized organized

15. flip 1 3 2 4 5 7 6 8 910 1112 1314 7 A B What terms are used to describe case A and case B

16. 1 3 2 4 5 7 6 8 910 1112 1314 flip 7 A B Case A is: attraction Case B is: repulsion

17. flip 1 3 2 4 5 7 6 8 910 1112 1314 8 Draw the representation of the direction of the magnetic field around the Earth.

18. 1 3 2 4 5 7 6 8 910 1112 1314 flip 8 The red part in each compass indicated the north. The field travels from north toward the south. Therefore the geographical north is the magnetic south.

19. flip 1 3 2 4 5 7 6 8 910 1112 1314 9 Use the two following pictures to explain the term ferromagnetic. Also state which three elements are known to be ferromagnetic.

20. 1 3 2 4 5 7 6 8 910 1112 1314 flip 9 Iron, nickel, cobalt are some common elements that show a unique magnetic behavior which is called ferromagnetism. Ferromagnetic materials have their unpaired electron spins to line up parallel with each other in a region called a domain if externally imposed magnetic field, say from a solenoid. Domains can align causing magnetism. Ferromagnets will tend to stay magnetized to some extent after being subjected to an external magnetic field.

21. flip 1 3 2 4 5 7 6 8 910 1112 1314 10 In the above left diagram, using the left-hand rule, what will be the direction of the current flow when the switch closes? Sometimes you meet two ideas of current: conventional current and electron current. Which current does the left-hand rule uses?

22. 1 3 2 4 5 7 6 8 910 1112 1314 flip 10 The purple line indicates the current used with the left-hand rule.

23. flip 1 3 2 4 5 7 6 8 910 1112 1314 11 + _ Use the left-hand rule to indicate the current, the motion and the direction of the field.

24. 1 3 2 4 5 7 6 8 910 1112 1314 flip 11 Remember that the electron flow is the current. The flow goes from north to south. The motion is upwards.

25. flip 1 3 2 4 5 7 6 8 910 1112 1314 12 Use the left-hand rule to show the current, the motion and the field.

26. 1 3 2 4 5 7 6 8 910 1112 1314 flip 12 Thu m b = motion ( in this case downward) F irst finger = field Se c ond finger = current

27. flip 1 3 2 4 5 7 6 8 910 1112 1314 13

28. 1 3 2 4 5 7 6 8 910 1112 1314 flip 13

29. flip 1 3 2 4 5 7 6 8 910 1112 1314

30. 1 3 2 4 5 7 6 8 910 1112 1314 flip 14

31. The END (exit program) 1 3 2 4 5 7 6 8 910 1112 1314 Paul Widergren © 2004 1 3 2 4 5 7 6 8 910 1112 1314