Exam 8 Numbers 11-15 PreAP

1. 11. Which of the following statements correctly describes the behavior of magnets?

A. Like poles attract each other, and unlike poles repel each other.

B. Like poles repel each other, and unlike poles attract each other.

C. Both like and unlike poles can attract and repel each other depending on the surrounding materials.

D. none of the above

Like poles repel each other, and unlike poles attract each other. This is because magnets have two poles, a north pole and a south pole. The north pole of one magnet is attracted to the south pole of another magnet, while the north pole of one magnet repels the north pole of another magnet. Similarly, the south pole of one magnet is attracted to the north pole of another magnet, while the south pole of one magnet repels the south pole of another magnet. This behavior is due to the magnetic field generated by the magnets.

Explanation

Like poles repel each other, and unlike poles attract each other. This is because magnets have two poles, a north pole and a south pole. The north pole of one magnet is attracted to the south pole of another magnet, while the north pole of one magnet repels the north pole of another magnet. Similarly, the south pole of one magnet is attracted to the north pole of another magnet, while the south pole of one magnet repels the south pole of another magnet. This behavior is due to the magnetic field generated by the magnets.

2. 14. Since more magnetic field lines cross the area that is near the pole of a magnet, what does this indicate about the magnetic field strength in that location?

A. It is stronger.

B. It is weaker.

C. It is entering the magnet.

D. It is leaving the magnet.

More magnetic field lines crossing a specific area near the pole of a magnet indicates that the magnetic field strength in that location is stronger. This is because the density of magnetic field lines represents the strength of the magnetic field. When more field lines are concentrated in a specific area, it indicates a higher magnetic field strength in that region.

Explanation

More magnetic field lines crossing a specific area near the pole of a magnet indicates that the magnetic field strength in that location is stronger. This is because the density of magnetic field lines represents the strength of the magnetic field. When more field lines are concentrated in a specific area, it indicates a higher magnetic field strength in that region.

3. 13. How is the direction of a magnetic field, B, defined at any location?

A. the direction toward which the south pole of a compass needle points

B. the direction toward which the north pole of a compass needle points

C. the direction that is parallel to the imaginary magnetic field lines

D. the direction that is perpendicular to Earth’s magnetic field

The direction of a magnetic field, B, is defined as the direction toward which the north pole of a compass needle points. A compass needle aligns itself with the magnetic field lines and the north pole of the needle is attracted to the south pole of a magnet. Therefore, by observing the direction in which the north pole of a compass needle points, we can determine the direction of the magnetic field.

Explanation

The direction of a magnetic field, B, is defined as the direction toward which the north pole of a compass needle points. A compass needle aligns itself with the magnetic field lines and the north pole of the needle is attracted to the south pole of a magnet. Therefore, by observing the direction in which the north pole of a compass needle points, we can determine the direction of the magnetic field.

4. 12. Which of the following statements about magnetic fields, B, is not true?

A. Magnetic fields are vector quantities.

B. Magnetic fields have both magnitude and direction.

C. Magnetic field strength increases as the distance from the magnetic source increases.

D. Magnetic fields are regions in which magnetic forces can be detected.

Magnetic field strength actually decreases as the distance from the magnetic source increases. This is because the magnetic field spreads out as it gets farther from the source, resulting in a decrease in the strength of the field.

Explanation

Magnetic field strength actually decreases as the distance from the magnetic source increases. This is because the magnetic field spreads out as it gets farther from the source, resulting in a decrease in the strength of the field.

5. 15. Which of the following statements about magnetic field lines is not true?

A. Magnetic field lines form open or closed loops.

B. Magnetic field lines appear to begin at the north pole of a magnet.

C. Magnetic field lines have no beginning or end.

D. Magnetic field lines appear to end at the south pole of a magnet.

The statement that magnetic field lines form open or closed loops is true. Magnetic field lines are continuous and form closed loops around a magnet. They start from the north pole of a magnet, curve around the magnet, and end at the south pole. This is why compass needles align with the magnetic field lines. Therefore, the correct answer is that magnetic field lines form open or closed loops.

Explanation

The statement that magnetic field lines form open or closed loops is true. Magnetic field lines are continuous and form closed loops around a magnet. They start from the north pole of a magnet, curve around the magnet, and end at the south pole. This is why compass needles align with the magnetic field lines. Therefore, the correct answer is that magnetic field lines form open or closed loops.

Exam 8 Numbers 11-15 Preap