Magnetism Revision

Which of the following statements correctly describes the behavior of magnets?

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

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

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

• none of the above

What do physicists call large groups of atoms whose net spins are aligned because of strong coupling between neighboring atoms?

• magnetic zones

• magnetic regions

• magnetic sectors

• magnetic domains

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

• Magnetic fields are vector quantities.

• Magnetic fields have both magnitude and direction.

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

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

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

• the direction toward which the south pole of a compass needle points

• the direction toward which the north pole of a compass needle points

• the direction that is parallel to the imaginary magnetic field lines

• the direction that is perpendicular to Earth’s magnetic field

 $What\ describes\ \Phi M$ ?

• magnetic flux.

• the number of field lines that cross a certain area.

• ABcos $\theta$  

• all of the above

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?

• It is stronger.

• It is weaker.

• It is entering the magnet.

• It is leaving the magnet.

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

• Magnetic field lines form open or closed loops.

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

• Magnetic field lines have no beginning or end.

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

Which of the following statements about the orientation and effects of Earth’s magnetic field is not true?

• The geographic North Pole of Earth is near the magnetic south pole.

• A compass needle that can rotate both perpendicularly and parallel to the surface of Earth, points down at the magnetic south pole.

• A compass needle always indicates the direction of true north.

• The geographic South Pole of Earth corresponds to the magnetic north pole.

Which of the following terms correctly describes the shape of the magnetic field around a long, straight current-carrying wire?

• cylindrical

• parallel

• perpendicular

• elliptical

In what direction do compass needles deflect in relation to the concentric circles of the magnetic field that is found around a current-carrying wire?

• away from the concentric circles

• perpendicular to the concentric circles

• toward Earth’s North Pole irrespective of the concentric circles

• tangential to the concentric circles