Download Chapter 20 EM Induction worksheet

Name: _____________________________ Class: __________________ Date: __________________
Electromagnetic Induction
Chapter Study Guide
Teacher Notes and Answers
1. e
2. a. 0.50 s
b. 0.26 m2
c. 2.6 V
3. a. magnetic field, conductor, relative motion
b. answers may vary, but could include the following: water wheel, windmill, electric
motor, combustion engine
4. a. 6.28 rad/s
b. 7.1  102 m2
c. 110 V
d. 78 V
5. A motor converts electric energy to rotational energy; generators converts rotational energy to
electric energy.
6. a. increases
b. induces current while change occurs
c. It decreases magnetic field which will induce a current while the change occurs.
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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Name: _____________________________ Class: __________________ Date: __________________
Electromagnetic Induction
Chapter Study Guide
1. Which of the following actions will induce an emf in a conductor?
a. Move a magnet near the conductor.
b. Move the conductor near a magnet.
c. Rotate the conductor in a magnetic field.
d. Change the magnetic field strength.
e. all of the above
2. A circular loop (10 turns) with a radius of 29 cm is in a magnetic field that
oscillates uniformly between 0.95 T and 0.45 T with a period of 1.00 s.
a. How much time is required for the field to change from 0.95 T to 0.45 T?
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b. What is the cross-sectional area of one turn of the loop?
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c. Assuming that the loop is perpendicular to the magnetic field, what is the
induced emf in the loop?
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3. Electric generators convert mechanical energy into electrical energy.
a. What are the requirements for generating emf?
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b. The mechanical energy input is usually rotational motion. What are two
possible sources of rotational motion?
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Chapter Study Guide continued
4. A 250-turn generator with circular loops of radius 15 cm rotates at 60.0 rpm in a
magnetic field with a strength of 1.00 T.
a. What is the angular speed of the loops?
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b. What is the area of one loop?
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c. What is the maximum emf?
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d. What is the rms emf?
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5. An electric motor is sometimes called a generator in reverse. Explain your
understanding of this statement.
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6. Consider a two-coil transformer joined by a common iron core.
a. If the current in the primary side is increased, what happens to the magnetic
field in the core?
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b. What effect does the answer to item 6a have on the secondary coil?
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c. Fully explain the effect of reducing the current to the primary side of a
transformer.
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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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