Download Guided Reading

Name ____________________________ Date ____________________ Class ____________
Using Electricity and Magnetism
■
Guided Reading and Study
What Is Electromagnetism?
This section explains how an electric current is related to a magnetic field. It also describes
characteristics of magnets and magnetic fields produced by electric currents.
Use Target Reading Skills
As you read the Solenoid section, write the main idea—the biggest or most important
idea—in the graphic organizer below. Then write three supporting details. The
supporting details further explain the main idea.
Main Idea
A solenoid is useful because its magnetic field can be changed.
Detail
a.
Detail
b.
Detail
c.
1. An electric current produces a magnetic ________________________.
2. What is electromagnetism?
_________________________________________________________________________
_________________________________________________________________________
3. Circle the letter of each sentence that is true about electric current and
magnetism.
a. A wire with a current has a magnetic field.
b. You can see electromagnetism around a wire.
c. Iron filings can map out a magnetic field around a wire with a current.
d. A wire with no current has a magnetic field.
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
Using Electricity and
Magnetism
Electric Current and Magnetism
Name ____________________________ Date ____________________ Class ____________
Using Electricity and Magnetism
■
Guided Reading and Study
What Is Electromagnetism? (continued)
Wire
Iron fillings
4. How can you tell that there is a current in the wire in the drawing?
_________________________________________________________________________
_________________________________________________________________________
Solenoids
5. What are the three characteristics of a magnetic field produced by a current?
a. ______________________________________________________________________
b.______________________________________________________________________
c. ______________________________________________________________________
6. How can you turn off a magnetic field produced by a current?
_________________________________________________________________________
7. Is the following sentence true or false? When the direction of the current reverses,
the direction of the magnetic field stays the same. _________________________
8. What is a solenoid?
_________________________________________________________________________
_________________________________________________________________________
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
Name ____________________________ Date ____________________ Class ____________
Using Electricity and Magnetism
■
Guided Reading and Study
9. Circle each of the sentences that is true about solenoids.
a. The strength of the magnetic field increases as the number of loops increases.
b. The north and south poles of a solenoid change with the direction of the current.
c. By winding a wire with a current into many loops, you weaken the magnetic
field in the center of the coil.
d. If wire with a current is twisted into a loop, the magnetic field lines become
bunched up inside the loop.
10. Suppose you wind a wire with a current into a coil. How have you
changed the wire’s magnetic field?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Electromagnets
11. Is the following sentence true or false? When iron is placed within a solenoid’s
magnetic field, the iron becomes a magnet. ________________________
12. What is an electromagnet?
_________________________________________________________________________
_________________________________________________________________________
13. In an electromagnet, what produces the temporary magnetic field?
_________________________________________________________________________
14. Describe four ways you can increase the strength of an electromagnet.
a. ______________________________________________________________________
______________________________________________________________________
b.______________________________________________________________________
______________________________________________________________________
c. ______________________________________________________________________
______________________________________________________________________
d.______________________________________________________________________
______________________________________________________________________
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
Using Electricity and
Magnetism
_________________________________________________________________________