Ch 7 Physical Test

Define magnetism.

• Magnetism is a physical phenomenon produced by the motion of electric charge, which results in attractive and repulsive forces between objects.

• Magnetism is the process by which materials become electrically charged.

• Magnetism is the ability of a substance to conduct electricity.

• Magnetism is the force that causes objects to fall to the ground.

How does magnetic force work?

• By attracting only metallic objects

• By creating a field that exerts force on other magnets and magnetic materials

• By repelling all non-metallic objects

• By generating electricity

In a magnetic field drawing, what does it indicate when the lines are closer to one another?

• Weaker field

• Stronger field

• No change

• Field disappears

What direction do magnetic field lines always point away from?

• North pole

• South pole

• East pole

• West pole

Why does a compass North needle point South?

• Because the North needle is attracted to the Earth's magnetic South pole.

• Because the North needle is repelled by the Earth's magnetic North pole.

• Because the North needle is attracted to the Earth's geographic North pole.

• Because the North needle is repelled by the Earth's geographic South pole.

Most scientists think about the Earth's magnetic field and poles as:

• Stable and unchanging

• Constantly shifting and reversing over time

• Weakening and disappearing

• Completely understood and predictable

Can you make a permanent magnet? If yes, how?

• Yes, by aligning the domains of a ferromagnetic material.

• No, it is not possible to make a permanent magnet.

• Yes, by cooling a material to absolute zero.

• Yes, by applying a strong electric field.

How can you increase the magnetic field on an electromagnet? Pick 2

• By increasing the resistance in the circuit

• By decreasing the voltage

• By increasing the number of turns in the coil

• By increasing the current flowing through the coil

What is the electromagnetic force?

• A force that acts between charged particles

• A force that acts only on neutral particles

• A force that acts only at very short distances

• A force that is weaker than gravitational force

True or False: Many loops of wire will have a greater field than a single loop.

• True

• False