Download Electric and Magnetic Forces and the Modern Day Compass

Electric and Magnetic Forces and the Modern Day Compass
Electric and Magnetic Forces and the Modern Day
Compass
If you go camping, chances are there won’t be any street signs to help direct you! That’s why
you need a compass to help you find your way using the power of electromagnetic force.
What is electromagnetic force?
Electromagnetic force is the interaction responsible for almost everything in daily life. Magnets
are objects that produce an area of magnetic force called a magnetic field.
Magnetic fields by themselves are invisible to the human eye. Magnets attract, or pull, objects
made with iron or other metals.
If you went camping, you’d use electromagnetic force to help you find the campsite and other
things located at specific points.
How does a compass work?
If you were trying to find your way in the forest, you would always hold it flat and look to the
red end of the needle, which always points north. This end points to the strongest magnetic
field, which is the earth’s Magnetic North Pole, in the Canadian Arctic.
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Electric and Magnetic Forces and the Modern Day Compass
If you needed to go southwest or northeast, you’d just check where those directions are in
relation to where you are standing and head in that direction to get there.
Opposites Attract
Even though magnets can come in different shapes, strengths, and sizes, they all have a north
and south pole, just like the earth has North and South Poles.
These ends of the magnets are the most powerful, and opposite magnetic poles attract, so the
north part of the needle actually points toward the south pole of a magnet. This is because the
needle is a magnet itself, and the red end that points toward north is the needle’s south pole,
which is attracted to the earth’s Magnetic North.
Fun fact
Earth itself is a very weak magnet! The earth's liquid core is believed to be a mix (alloy) of iron
and nickel, giving the earth its own magnetic field.
© 2013 ReadWorks®, Inc. All rights reserved.
Questions: Electric and Magnetic Forces and the Modern Day Compass
Name:
_____________ Date: _______________________
1. What is a compass used for?
A.
B.
C.
D.
to
to
to
to
produce an area of magnetic force
attract objects made of metal
help people find their way
find animals in the forest
2. Why does the author describe the way a compass works?
A.
B.
C.
D.
to
to
to
to
explain the electromagnetic forces involved
show that they are very complicated to use
argue that everyone should own a compass
describe the materials it is made of
3. Read the following sentence: “Electromagnetic force is the interaction responsible for
almost everything in daily life.”
What conclusion below can be drawn from the sentence above?
A. Electromagnetic force only occurs in the daytime.
B. Without electromagnetic force, daily life would be different from how we
experience it now.
C. Electromagnetic force explains what is responsible for how we live our lives.
D. With electromagnetic force, anything is possible.
4. The needle of the compass is attracted to which of the following?
A.
B.
C.
D.
the
the
the
the
needle’s North Pole
earth’s South Pole
needle’s South Pole
earth’s North Pole
5. What is this passage mainly about?
A.
B.
C.
D.
camping
electromagnetic forces and the compass
the needles of a magnet
the poles of the earth
1
®
© 2013 ReadWorks , Inc. All rights reserved.
Questions: Electric and Magnetic Forces and the Modern Day Compass
6. Read the sentence: “If you needed to go southwest or northeast, you’d just check
where those directions are in relation to where you are standing and head in that
direction to get there.”
As used in the passage, what does the word “head” mean?
A.
B.
C.
D.
a part of the human body
a person leading something
to go
to lead
7. Choose the answer that best completes the sentence below.
Magnets are different in shape and size ________ they all have a north and south pole.
A.
B.
C.
D.
and
but
so
if
8. Which direction does the red end of the needle of a compass point?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
2
®
© 2013 ReadWorks , Inc. All rights reserved.
Questions: Electric and Magnetic Forces and the Modern Day Compass
9. What do all magnets have?
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
10. The needle of a compass is a magnet. Use evidence from the text to support this
statement.
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
3
®
© 2013 ReadWorks , Inc. All rights reserved.
Teacher Guide & Answers: Electric and Magnetic Forces and the Modern Day Compass
Teacher Guide & Answers
Passage Reading Level: Lexile 1190
1. What is a compass used for?
A.
B.
C.
D.
to produce an area of magnetic force
to attract objects made of metal
to help people find their way
to find animals in the forest
2. Why does the author describe the way a compass works?
A.
B.
C.
D.
to explain the electromagnetic forces involved
to show that they are very complicated to use
to argue that everyone should own a compass
to describe the materials it is made of
3. Read the following sentence: “Electromagnetic force is the interaction responsible for almost
everything in daily life.”
What conclusion below can be drawn from the sentence above?
A. Electromagnetic force only occurs in the daytime.
B. Without electromagnetic force, daily life would be different from how we
experience it now.
C. Electromagnetic force explains what is responsible for how we live our lives.
D. With electromagnetic force, anything is possible.
4. The needle of the compass is attracted to which of the following?
A.
B.
C.
D.
the needle’s North Pole
the earth’s South Pole
the needle’s South Pole
the earth’s North Pole
5. What is this passage mainly about?
A.
B.
C.
D.
camping
electromagnetic forces and the compass
the needles of a magnet
the poles of the earth
© 2013 ReadWorks®, Inc. All rights reserved.
Teacher Guide & Answers: Electric and Magnetic Forces and the Modern Day Compass
6. Read the sentence: “If you needed to go southwest or northeast, you’d just check where
those directions are in relation to where you are standing and head in that direction to get there.”
As used in the passage, what does the word “head” mean?
A.
B.
C.
D.
a part of the human body
a person leading something
to go
to lead
7. Choose the answer that best completes the sentence below.
Magnets are different in shape and size ________ they all have a north and south pole.
A.
B.
C.
D.
and
but
so
if
8. Which direction does the red end of the needle of a compass point?
Suggested answer: The red end of the needle always points north.
9. What do all magnets have?
Suggested answer: All magnets have a north and south pole.
10. The needle of a compass is a magnet. Use evidence from the text to support this statement.
Suggested answer: Students should explain that all magnets have a north and a south pole.
The red end of the needle is the needle’s south pole which always points north because it is
attracted to the earth’s North Pole as opposite magnetic poles attract. Thus, it can be concluded
that the needle of a compass is a magnet.
© 2013 ReadWorks®, Inc. All rights reserved.