Download directed_reading_Magnetism and Electricity p518-52

Name ______________________________ Class ___________________ Date __________________
Skills Worksheet
Directed Reading -Magnetism and
Electricity p.518-523
Section: Magnetism from Electricity
Circle the letter of the best answer for each question.
THE DISCOVERY OF ELECTROMAGNETISM
1. Why does a compass needle move when it is near a magnetic field?
a. A compass needle is a magnet.
b. A compass needle is not a magnet.
c. The wire has an electric current.
d. The wire does not carry an electric current.
More Research
2. What does an electric current make?
a. a magnetic compass
b. a magnetic pole
c. a magnetic field
d. an aurora
3. What direction does a magnetic field take?
a. The direction the compass moves.
b. The direction of the electric current.
c. The direction the magnet moves.
d. The direction of the water current.
USING ELECTROMAGNETISM
4. What is the interaction between electricity and magnetism called?
a. magnetic field
b. magnetic current
c. electromagnetism
d. solenoid
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Name ______________________________ Class ___________________ Date __________________
Directed Reading B continued
Circle the letter of the best answer for each question.
5. What two things make the magnetic field of a current-carrying wire
stronger?
a. a galvanometer and a compass
b. a galvanometer and a solenoid
c. an electromagnet and a compass
d. an electromagnet and a solenoid
Solenoids
6. What is a coil of wire that produces a magnetic field when carrying an
electric current called?
a. a galvanometer
b. a doorbell
c. a compass
d. a solenoid
Electromagnets
7. What is a solenoid wrapped around an iron core called?
a. a galvanometer
b. an electromagnet
c. a compass
d. an armature
8. What happens if you add more electric current to the solenoid wire?
a. The electromagnet gets stronger.
b. The electromagnet gets weaker.
c. The electromagnet changes direction.
d. The electromagnet stays the same.
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Electromagnetism
Name ______________________________ Class ___________________ Date __________________
Directed Reading B continued
Circle the letter of the best answer for each question.
9. What is one way to make an electromagnet stronger?
a. Make more loops in the solenoid.
b. Make fewer loops in the solenoid.
c. Make the solenoid loops larger.
d. Make the solenoid loops smaller.
Turning Electromagnets On and Off
10. What happens when an electromagnet is turned off?
a. The electromagnet is still very useful.
b. The electric current stays on.
c. The electromagnet still attracts things.
d. The electromagnet no longer attracts things.
APPLICATIONS OF ELECTROMAGNETISM
Read the description. Then draw a line from the dot next to each
description to the matching word.
11. uses two solenoids to make
both sound and light
12. changes electrical energy into
mechanical energy
13. measures electric current
14. coil of wire between a
magnet’s north and south
poles
15. uses brushes to make electric
current reverse directions
•
•
•
•
•
a. galvanometer
b. doorbell
c. electric motor
a. commutator
b. armature
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Electromagnetism
Name ______________________________ Class ___________________ Date __________________
Skills Worksheet
Section Review p523
Magnetism from Electricity
USING KEY TERMS
For the pair of terms, explain how the meanings of the terms differ.
1. electromagnet and solenoid
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UNDERSTANDING KEY IDEAS
_____ 2. Which of the following actions will decrease the strength of the
magnetic field of an electromagnet?
a. using fewer loops of wire per meter in the coil
b. decreasing the current in the wire
c. removing the iron core
d. All of the above
3. Describe what happens when you hold a compass close to a wire carrying a
current.
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4. What is the relationship between an electric current and a magnetic field?
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5. What makes the armature in an electric motor rotate?
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CRITICAL THINKING
6. Applying Concepts What do Hans Christian Oersted’s experiments have to do
with a galvanometer? Explain your answer.
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Electromagnetism
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Section Review continued
7. Making Comparisons Compare the structures and magnetic fields of solenoids
with those of electromagnets.
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INTERPRETING GRAPHICS
8. Look at the image in your textbook for this Section Review. Your friend says
that the image shows an electromagnet because there are loops with a core in
the middle. Is your friend correct? Explain your reasoning.
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Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
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Electromagnetism