Grade 8 Magnetic Forces Quiz

What type of force might be affecting the motion of the floating rings?

• Frictional force

• Nuclear force

• Magnetic force

• Gravitational force

What happens to the magnetic poles when a magnet is split into two?

• Each half retains both north and south poles.

• One half becomes the north pole and the other half becomes the south pole.

• Both halves lose their magnetic properties.

• One half becomes magnetic and the other half becomes non-magnetic.

What effect does distance seem to have on the strength of the magnetic force?

• The strength of the magnetic force increases with distance.

• The strength of the magnetic force is not affected by distance.

• The strength of the magnetic force decreases with distance.

• The strength of the magnetic force remains constant regardless of distance.

How did the screwdriver become temporarily magnetic?

• Magnetic domains formed in the metal of the screwdriver when it was exposed to the magnet.

• The magnetic domains in the screwdriver were temporarily aligned by the presence of the magnet.

• The magnet erased the magnetic domains in the screwdriver.

• The force exerted by the screws made the magnetic domains in the metal of the screwdriver line up.

Which statement describes the net magnetic force exerted by the iron particle with 100 atoms with the north pole pointed to the left and 100 pointed to the right?

• The net magnetic force is 200 times as strong as the force of the atoms.

• The net magnetic force is 100 times as strong as the force of the atoms.

• The net magnetic force is less than zero.

• The net magnetic force is about zero.

When a magnet is cut in half, both halves become magnets with north and south poles. Which statement describes the four bars that are produced?

• Two pieces would only have south poles and the other two pieces would only have north poles.

• Each piece would have one magnetic pole and a nonmagnetic end.

• Each piece would have a north pole and a south pole.

• The poles within each magnetic domain in lodestones line up, but they cancel each other out within each domain in iron.

Iron nails are attracted to magnets, but they are not attracted to each other. Explain why iron nails may behave this way.

• The magnetic domains in lodestones cannot change their alignment, but those in iron are free to change their orientation.

• The magnetic atoms are randomly oriented.

• The magnetic domains in the iron nails are randomly oriented.

• The poles within each magnetic domain in lodestones line up, but they cancel each other out within each domain in iron.

In a small iron particle made of 200 atoms, the north poles of 100 atoms are pointed right and the north poles of another 100 atoms are pointed left. Which statement describes the net magnetic force exerted by the iron particle?

• The net magnetic force is about zero.

• The net magnetic force is 200 times as strong as the force of the atoms.

• The net magnetic force is less than zero.

• The net magnetic force is 100 times as strong as the force of the atoms.

If the magnet on the right is flipped so that the south pole is on the left, the magnetic force will be

• Attractive

• None of the above

• Neutral

• Repulsive

As the two magnets are moved closer together, the magnetic force between them will become

• Stronger

• Neutral

• None of the above

• Weaker