Chapter 2:
Magnetism
Practice Test
1.
Where are the magnetic field lines closest together in the magnetic field surrounding a bar magnet?
a.
It is impossible to say.
b.
between the poles
c.
away from the poles
d.
at the poles
Hint
2.
What happens when a conductor experiences changing magnetic field?
a.
The conductor begins to vibrate.
b.
An electric current is induced in the conductor.
c.
away from the poles
d.
All of the above.
Hint
3.
Suppose you find a bar of magnetite and you hang it from a string. The bar swings freely in the air, but the two ends of the bar tend to point north and south. What are the two ends of the bar called?
a.
magnetic fields
b.
magnetic poles
c.
a dial compass
d.
leading poles
Hint
4.
How do loudspeakers work?
a.
A constantly changing electric signal moves through a coil of wire.
b.
A coil of wire is used to make an electromagnet.
c.
a dial compass
d.
All of the above.
Hint
5.
Suppose you take two bar magnets and you slowly move the north poles of the magnets closer to one another. What do you observe?
a.
The poles attract and the force between the poles increases.
b.
The poles repel and the force between the poles increases.
c.
The poles attract and the force between the poles decreases.
d.
The poles repel and the force between the poles decreases.
Hint
6.
High-voltage wires are best for long distance electrical wires, but are dangerous for household use. A transformer may be used to change the voltage to an appropriate amount. What is the working principle behind a transformer?
a.
Spinning a coil of wire near a permanent magnet induces a current.
b.
An electrical current in one wire is used to induce a current in another wire.
c.
Electrical energy is converted to mechanical energy, then back to electrical energy.
d.
All of the above.
Hint
7.
It is possible to construct a magnet using a coil of wire and a battery. What can you do with the wire to increase the strength of the magnetic field of your electromagnet?
a.
wrap the coil of wire around an iron bar
b.
increase the number of coils in the wire
c.
increase the voltage of the battery
d.
All of the above.
Hint
8.
The magnetic field of Earth protects us from high-energy, charged particles from the sun. What is the fate of the charged particles that encounter Earth's magnetic field?
a.
Particles are trapped in a region over the equator called the Van Allen Belts.
b.
Particles interact with gases in the atmosphere to create the northern lights.
c.
Particles interfere with radio reception and electrical power lines.
d.
All of the above.
Hint
9.
Suppose a charged particle from the sun is traveling through Earth's magnetic field. What effect does the magnetic field have on this moving charge?
a.
The magnetic field exerts a force on the particle at right angles to the lines of the magnetic field.
b.
The magnetic field has no effect on the direction of the traveling particle.
c.
The magnetic field exerts a force on the particle in the direction of the magnetic field.
d.
All of the above.
Hint
10.
How are magnetic domains related to magnetism?
a.
The magnetic fields of the domains of non-magnetic substances are not aligned.
b.
The magnetic fields of domains of magnetic substances are aligned.
c.
The magnetic field exerts a force on the particle in the direction of the magnetic field.
d.
All of the above.
Hint
11.
A thousand years ago, the Chinese used needles of lodestone to navigate their ships. What kind of magnet were these mariners using?
a.
temporary magnets
b.
electromagnets
c.
permanent magnets
d.
induced magnets
Hint
12.
If two bar magnets, with labeled north and south poles, are brought close together and allowed to interact, what might you observe?
a.
Two north poles repel, two south poles attract.
b.
Like poles repel, different poles attract.
c.
Like poles attract, different poles repel.
d.
Two north poles attract, two south poles repel.
Hint
13.
How does Magnetic Resonance Imaging work?
a.
A changing magnetic field is used to perform surgery without cutting.
b.
A large magnet helps the body repair arthritic joints.
c.
Like poles attract, different poles repel.
d.
All of the above.
Hint
14.
If a bar magnet is brought near an iron nail, the nail becomes magnetic and is attracted to the bar magnet. What is the term used to describe the magnetism of the iron nail?
a.
electromagnetism
b.
magnetic domination
c.
temporary magnetism
d.
induced magnetism
Hint
15.
What is the working principle behind an electric generator?
a.
Spinning a coil of wire near a permanent magnet induces a current.
b.
Electrical energy is converted to mechanical energy.
c.
An electrical current in one wire is used to induce a current in another wire.
d.
All of the above.
Hint
