Download Forces Study Guide: Magnets

Name: __________________________________ Block: _____ Date: ________
Forces Study Guide: Magnets
Study your notes from the following lessons:
1. What are the properties of magnets?
2. How are electricity and magnetism related?
3. How would one investigate the basic principles of an electromagnet?
4. How can you distinguish between the Earth’s magnetic field, fields that surround a magnet, and an
electromagnet?
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1.
Define magnet: is any material that produces a magnetic field and attracts or repels other materials
containing iron, nickel, or cobalt.
2.
Define magnetism: is the force of attraction or repulsion of a magnetic material due to the arrangement of
its atoms.
3.
List and describe the four types of magnets:
a. Natural magnets – found in nature (magnetite). Originally discovered 2000 years ago in China
and Greece.
b. Electromagnets – strong magnets that are created by combining magnets and electricity.
c. Permanent magnets – retain their magnetism (harder to make)
d. Temporary magnets – lose their magnetism (easy to create)
4. List five basic properties of magnets: always have north and south poles (domains); “like” poles repel
“opposite” poles attract; if you cut a magnet in half each piece has a north and south pole; made of (and
attracts) iron, nickel, or cobalt; creates a field around the object; attraction is strongest at the poles; field is
represented by “force lines” (or “magnetic field lines”); the Earth has a magnetic field due to its charged
iron/nickel core.
5. List two ways to demagnetize a magnet: drop it or boil (heat) it.
6. What do you end up with if you cut a magnet in half? 2 magnets, each with a north and south pole.
7.
Define a domain: groups of atoms that are sectioned off in tiny areas.
8.
Draw a picture that represents the domains of a substance that is magnetized, and one that is not.
9.
What is the magnetic field of a magnet? The region where the magnetic forces act is called the magnetic
field.
10.
How can you make the magnetic field of a magnet visible? Pour iron filings (shavings) on the magnet.
11.
What is the name of the Earth’s magnetic field? The Magnetosphere
Name: __________________________________ Block: _____ Date: ________
12.
List two effects of the Earth’s magnetic field: It causes a compass to point to Earth’s magnetic south pole
(our geographic North pole) and causes the northern and southern lights to appear when particles from
the sun hit the magnetosphere.
13.
The marked end of a compass always points to a magnets SOUTH pole. Is the needle of the compass
pointing to Earth’s geographic north? Explain why/why not. The needle of the compass IS pointing to our
geographic North pole, but it is Earth’s magnetic south pole. Opposites attract!
14.
What do electric currents, solenoids, bar magnets, and the Earth have in common? They all have a
magnetic field, a north and south pole, attraction to iron, nickel, and cobalt.
15.
Who discovered that wires containing electric current have magnetic fields? How did he/she discover
this information? Hans Christian Oersted was giving a lecture on compasses and held the compass too
close to a live wire. When he did this he noticed that the marked needle no longer pointed to Earth’s
geographic north pole, but instead towards the wire.
16.
Draw and label an electromagnet. (On the magnet, make sure the solenoid, battery, iron core, and
magnetic field are labeled.)
magnetic
field
iron core
solenoid
battery
17.
A coil of wire with an electric current in it is called a solenoid.
18.
List two ways to strengthen the magnetic field of an electromagnet:
a. Add more power to the power source (bigger battery/more volts).
b. Make more loops in the solenoid (loops closer together).
19.
When a magnet (iron core) moves through a wire coil (solenoid) an electric current is created.
20.
When wires spin or alternate between two magnets electricity is created. Magnets can create electricity
and electricity can create magnets.