Student Number:

Name: _____________________________ Room: _____ Date: __________________Grade: 4 Unit 1: Magnetism and Electricity Science Homework______________________________________________________________________

Homework packet link: https://sites.google.com/a/ccs-rams.org/pan/

1. Circle the objects below that stick to magnet.

steel screen soda straw

aluminum nail iron nail

steel paper clip rubber band

brass ring black rock (magnetite)

2. Unlike poles ___________________.

3. Like poles ___________________.

4. ___________________ is a specific kind of force.

5. Every magnet has a north pole and ___________________.

6. A force is a push or ___________________.

7. A ___________________is an object that sticks to iron or steel.

8. When magnets push apart, we say they ___________________.

9. When magnets pull together, we say they ___________________.

10. The magnets shown on page 8 of the Science Resources book have one pole labeled. Which pairs of magnets will attract? Circle the letters below.

a. b. c. d. e.

11. Why does the mineral magnetite stick to a magnet?

___________________________________________________________________

12. What happens if the two magnets are broughttogether as you see in Box A? Box AA. They will repel.

B. They will attract.

C. Nothing will happen.

13. What happens if the two magnets are broughttogether as you see in box B? Box B

A. They will repel.

B. They will attract.

C. Nothing will happen

14. Some magnets like your doughnut magnets are magnets all the time. They are

called ___________________ magnets.

15. When a permanent magnet touches an iron objects, that iron object becomes a

___________________ magnet. It stays a magnet as long as it is in the invisible

___________________ field of the permanent magnet.

16. ___________________ magnetism is the temporary magnetism that occurs in a

piece of iron when it interacts with a magnetic field.

17. How does distance affect the ability of a magnet to attract a piece of iron?

___________________________________________________________________

___________________________________________________________________

18. In a scientific investigation, you should do ___________________ (three or more) to confirm your result.

19. The ___________________ of two lines is the point at which they cross.

20. A ___________________ organizes data visually to show a relationship between

two things.

21. A ___________________is an educated guess based on data or previous

experience.

22. What happens to the strength of attraction between two magnets as the distance

between them increases?

___________________________________________________________________

___________________________________________________________________

23. A ___________________ is something you use to gather evidence about

something you can’t see.

24. A ___________________is a magnet used to detect Earth’s magnetic field.

25. A student placed two compasses on a box to detect a square magnet that was hidden inside. The black square shows where the magnet was hidden. Which drawing shows how the compasses looked when she found the magnet? Circle the letter.

A B

C D

26. ___________________electricity is separation of positive and negative charge.

27. ___________________charge occurs when an object loses electrons.

28. An ___________________is a tiny particle that is part of an atom. It is responsible for

charge on objects.

29. Two objects ___________________ each other when both have positive charge

or both have negative charge.

30. ___________________charge occurs when an object has extra electrons.

31. Two objects ___________________ each other when one has positive charge

and the other has negative charge.

32. What causes two charged balloons to repel each other?

___________________________________________________________________

___________________________________________________________________

33. Wanda rubbed a plastic rod with a piece of wool. The rod had a negative charge. Then she rubbed a balloon on a string with the same piece of wool. When she brought the plastic rod close to the balloon, the balloon moved away from the plastic rod.

When Wand saw this, she knew the balloon(Circle the correct answer.)

A. must have had a negative charge.

B. must have had no charge.

C. must have had a positive charge.

34. A ___________________ is a pathway for the flow of electricity.

35. An electricity ___________________ is component that changes electricity into

another form of energy such as light or heat.

36. ___________________electricity flows from the negative end of the cell to the

positive end of the cell.

37. A ___________________ refers to more than one cell.

38. D-cells, bulbs, and wires are all circuit ___________________.

39. A short circuit is a direct pathway from one end of a battery to the other end.

40. Thomas Edison’s light bulb was an energy converter. What does that mean?

___________________________________________________________________

___________________________________________________________________

41. Circle which circuits will light a bulb.

A B C

D E F

42. A ___________________is the thin wire in a lightbulb that makes light when

heated by an electric current.

43. A motor is a component in a circuit that converts electric energy to

___________________energy.

44. A ___________________ is a device used to open and close circuits.

45. An ___________________circuit is an incomplete circuit through which

electricity will not flow.

46. A ___________________diagram is a way to represent a circuit on a piece of

paper.

47. A ___________________circuit is a complete circuit through which electricity

flows.

48. A ___________________is a metal that connects wires in a circuit.

49. A ___________________holds many components needed to build a circuit.

50. What does a motor do in a circuit?

___________________________________________________________________

51. Draw a schematic diagram inside the box showing a complete circuit using the following components:

D-cell

bulb

switch

52. Draw a schematic diagram inside the box showing a complete circuit using the following components:

D-cell

motor

switch

53. The bulb in lamp converts electric energy into ___________________ and heat.

54. A fan converts electric energy into ___________________.

55. A doorbell converts electric energy into ___________________.

56. A toaster converts electric energy into ___________________.

57. An ___________________is a material that prevents the flow of electricity.

58. A ___________________ is a substance through which electricity will flow.

59. Circle the objects below that are conductors.

nail water

plastic cup metal screen

air glass

metal spoon copper wire

pencil board marker

60. How do you know if a material is a conductor or an insulator?

___________________________________________________________________

___________________________________________________________________

61. When two bulbs are connected in one big circuit, so that the electric current has

to go through all the components one at a time, that is a

___________________circuit.

62. To ___________________an object is to position it in a certain way.

63. Why do you think the two lightbulbs are dim when only one battery is used?

___________________________________________________________________

___________________________________________________________________

64. Look at the two bulb-and-battery circuits pictured below. Only one will light the bulb. Circle the one that you think will work.

65. Look at the pictures below. If the bulb will light or the motor will run, write “yes” in the box below the circuit. Write “no” if the bulb will not light or the motor will not run.

A B

C D

E F

66. A ___________________ circuit has two or more pathways for electric current to flow through.

67. What is the advantage of wiring two lightbulbs in parallel?

___________________________________________________________________

___________________________________________________________________

68. Look at the circuits below. If it is a series circuit, write S on the blank line above each drawing. If it is a parallel circuit, write P on the blank line.

A. B. C. D.

69. Draw schematic diagrams of the above circuits A and B in the boxes below.

schematic diagram of circuit A

schematic diagram of circuit B

70. ___________________ current is a flow or electricity through a conductor.

71. A ___________________is wire wound repeatedly around a central core.

72. An ___________________ is a coil of insulated wire, usually wound around a

core of iron or ___________________ which produces a magnetic field when

electricity flows through the wire.

73. The ___________________is the mass of iron or steel around which a wire is

wound.

74. If you put a compass near a wire that has a electricity flowing through it, the compass needle changes direction. The needle moves because(Circle the correct answer.)

A. it is lining up with Earth’s North Pole.

B. a compass needs electricity in order to work.

C. the electricity in the wire produces a magnetic field.

75. A ___________________ is a way to display the relationship between variables.

76. A ___________________ is an educated guess based on knowledge or

information.

77. How does the number of winds on an electromagnet core affect the strength of

the magnetism?

_________________________________________________________

78. Graph the data shown on the table below.

Wire Size 1 2 3 4 5 6 7 8Number of Washers 3 5 7 10 13 15 17 20

Strength of the Electromagnet

                                                                                     

                                  

79. Mark an X next to the materials you would need to build an electromagnet.

_____ wire _____ aluminum rivet

_____ motor _____ iron rivet

_____ D-cell _____ string

_____ lightbulb _____ switch (optional)

80. A ___________________is a set of signals that represents letters or words for sending messages.

81. A ___________________ is a device for sending coded messages by signals produced by closing and opening an electric circuit.

82. The ___________________ is the space between the steel strip and the electromagnet.

83. A telegraph ___________________is a switch that completes the circuit in a telegraph system.

84. Read “Morse Gets Clicking.” Using the present-day Morse code, decode these suggestions below from Morse when your telegraph does not have enough power to make a click.

A

A ____________________________________________

B

B ____________________________________________

85. Sarena heard that if you wind a wire around a rivet and connect the wire to a D-cell, you can make a magnet. She got some wire, wound it around an aluminum rivet four times, and attached it to a D-cell. She tried to pick up some paper clips, but nothing happened.

Below is the drawing she made to show what she had done. Help Sarena get her electromagnet to work by drawing what she needs to change.

Sarena’s drawing Your drawing aluminum rivet 4 winds

of wire

86. ___________________ – means craft or skill; -logy means science of - is using science to make something useful.

87. ___________________refers to something that is far away.88. Draw a circle around each device below that uses an electromagnet.

motor doorbell lamp earphones

89. Complete the circuits of these two telegraphs for two-way communication.