Plotting magnetic fields

9.What shape is Earth's magnetic field similar to?

10.The geographic North pole of Earth is near which magnetic pole?

11.What happens to a plotting compass when placed near a bar magnet?

12.Why can't iron filings show the direction of a magnetic field?

13.A student places a plotting compass near the north pole of a bar magnet. Which direction will the north pole of the compass needle point?

14.The diagram shows the magnetic field lines around a bar magnet. At which point is the magnetic field strongest?

15.A student uses a plotting compass to map the magnetic field around a bar magnet. She places the compass at several positions and marks the direction of the needle. Which of the following best describes the pattern of the arrows she draws?

16.Which of the following materials is magnetic?

17.The Earth's magnetic field is similar in shape to the field of a:

18.A student places a plotting compass near a wire carrying a direct current. The compass needle deflects. What does this demonstrate?

19.A plotting compass is placed at point X near a bar magnet. The compass needle points towards the south pole of the magnet. What does this indicate about the magnetic field direction at X?

20.A student sets up an experiment to compare the strength of the magnetic field at different distances from a bar magnet. She uses a plotting compass and measures the angle of deflection from north. Which of the following should she keep constant?

21.The Earth's outer core is made of molten iron and nickel. Why does this produce a magnetic field?

22.A compass is used for navigation. If you are at the geographic North Pole, which direction would a compass needle point?

23.In an experiment, a student places a bar magnet under a sheet of paper and sprinkles iron filings on top. The filings form a pattern. Which of the following statements about this method is correct?

24.Which of the following is the correct method to map the magnetic field around a bar magnet using a plotting compass?

25.A student uses a plotting compass to map the magnetic field around a bar magnet. She places the compass at position A and the north pole of the compass needle points toward the south pole of the magnet. She then moves the compass to position B and the north pole of the needle points toward the north pole of the magnet. What can be concluded about positions A and B?

26.A student places a bar magnet under a sheet of paper and sprinkles iron filings on top. The filings form a pattern showing the magnetic field lines. She then places a plotting compass at a point where the filings are dense. The compass needle aligns at an angle to the visible field line. What is the most likely explanation?

27.A plotting compass is placed near a wire carrying a large direct current. The compass needle deflects. What does this demonstrate?

28.A student sets up a circuit with a battery, a switch, and a long straight wire. She places a plotting compass near the wire. When the switch is closed, the compass needle deflects. She reverses the connections to the battery so the current flows in the opposite direction. What will happen to the compass needle?

29.A student wants to compare the strength of the magnetic field at different distances from a bar magnet. She uses a plotting compass and measures the angle of deflection from north. Which of the following procedures will give the most reliable results?

30.A student places a plotting compass near the north pole of a bar magnet. The north pole of the compass needle points away from the magnet. She then moves the compass to the south pole of the magnet. Which direction will the north pole of the compass needle point?

31.A student places a bar magnet on a table and uses a plotting compass to map its magnetic field. She notices that the compass needle does not point exactly along the expected field line direction. Which of the following is the most likely reason?

32.What is a plotting compass made of?

33.Which of the following statements is true?

34.A student uses a plotting compass to map the magnetic field around a bar magnet. She places the compass at several positions and marks the direction of the needle. Which of the following best describes what the final pattern of arrows shows?

35.A student places a bar magnet under a sheet of paper and sprinkles iron filings on top. The filings form a pattern. She then places a plotting compass at point X and the compass needle points towards the south pole of the magnet. Which of the following is a correct conclusion?

36.A student sets up a circuit with a battery, a switch, and a long straight wire. She places a plotting compass near the wire. When the switch is closed, the compass needle deflects. What does this demonstrate?

37.A student wants to compare the strength of the magnetic field at different distances from a bar magnet. She uses a plotting compass and measures the angle of deflection of the needle from its usual north-south alignment. Which of the following is a valid conclusion?

38.A student places a plotting compass near the north pole of a bar magnet. The north pole of the compass needle points away from the magnet. She then moves the compass to a point where the needle points towards the magnet. Which of the following could be the new position?

39.A compass needle points towards Earth's magnetic south pole. Which geographic pole is near Earth's magnetic south pole?

40.The diagram shows magnetic field lines around a bar magnet. At which point is the magnetic field strongest?

41.A compass points towards Earth's magnetic north.

42.A compass can be used for navigation.

43.The geographic North pole of Earth is near its magnetic south pole.

44.What does a plotting compass contain?

45.Match each item on the left with its correct description on the right.

46.Arrange the steps to correctly map a magnetic field using a plotting compass.

47.Which of the following are magnetic metals? (Select all that apply)

48.A plotting compass is a small bar magnet that is free to rotate.

49.A plotting compass is placed near a bar magnet. The north pole of the compass needle points towards the south pole of the bar magnet. Which of the following is correct?

50.Which of the following statements about Earth's magnetic field are true? (Select all that apply)

51.Complete the sentence.

52.State the three magnetic metals (including the two in the Earth's outer core).

53.State one benefit of using a plotting compass over iron filings to investigate a magnetic field.

54.Describe why a compass should not be used near an electronic device such as a mobile phone.

55.State where the Earth's magnetic field is strongest, using the diagram of Earth's magnetic field.

56.Explain whether we would be able to use compasses to navigate if the Earth did not have a magnetic field.

57.A student places a plotting compass 5 cm from the north pole of a bar magnet. The compass needle points away from the magnet. She then moves the compass to 10 cm from the same pole. What is the ratio of the magnetic field strength at 5 cm to that at 10 cm? (Assume the field behaves like a point dipole.)

58.Complete the sentences.

59.A plotting compass is placed 2 cm from the north pole of a bar magnet. The compass needle deflects by 30°. When the compass is moved to 4 cm from the same pole, the deflection is 10°. Assuming the magnetic field strength is proportional to the tangent of the deflection angle, calculate the ratio of the field strength at 2 cm to that at 4 cm.

60.State where the magnetic field is strongest on Earth. Explain, using the diagram of Earth's magnetic field, how we know this.

61.A student places a plotting compass 5 cm from the north pole of a bar magnet. The compass needle points away from the magnet. She then moves the compass to 10 cm from the same pole. What is the ratio of the magnetic field strength at 5 cm to that at 10 cm? (Assume the field behaves like a point dipole.)

62.A plotting compass is placed 2 cm from the north pole of a bar magnet. The compass needle deflects by 30°. When the compass is moved to 4 cm from the same pole, the deflection is 10°. Assuming the magnetic field strength is proportional to the tangent of the deflection angle, calculate the ratio of the field strength at 2 cm to that at 4 cm.