Download Chapter 36 and 37 Practice Test

Name: ________________________ Class: ___________________ Date: __________
ID: A
Magnetism
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Changing the magnetic field intensity in a closed loop of wires induces
a. current.
b. voltage.
c. both current and voltage.
d. neither current nor voltage.
____
2. A device that transforms mechanical energy to electrical energy is a
a. generator.
b. transformer.
c. magnet.
d. motor.
e. none of the above
____
3. If a magnet is pushed into a coil, voltage is induced across the coil. If the same magnet is pushed into a coil
with more loops:
a. a larger voltage is induced.
b. a smaller voltage is induced.
c. the same voltage is induced.
____
4. A transformer works because
a. electricity flows from a primary coil to a secondary coil.
b. electricity is induced in a rotating coil.
c. a changing magnetic field is transferred to a coil via an iron core.
d. electricity is transferred to a coil via an iron core.
____
5. The voltage across the input terminals of a transformer is 140 V. The primary has 20 loops and the secondary
has 10 loops. The voltage the transformer puts out is
a. 10 V.
b. 70 V.
c. 140 V.
d. 280 V.
e. none of the above
____
6. The induced voltage in a coil is proportional to
a. the number of loops.
b. the rate at which the magnet moves through those loops of coil.
c. the rate at which the loops of coil move around the magnet.
d. all of the above.
____
7. If you break a bar magnet in half, each half
a. becomes a bar magnet with two poles.
b. becomes unmagnetized.
c. contains one magnetic pole.
1
Name: ________________________
ID: A
____
8. If you put a small compass in a magnetic field, the compass will
a. line up in a direction parallel to the magnetic field lines.
b. swing randomly.
c. line up in a direction perpendicular to the magnetic field lines.
d. seek electrical charge concentrations.
____
9. When current passes through a wire, a magnetic field is created around the wire only if the
a. wire is absolutely straight.
b. wire is curved in a loop.
c. current makes a complete loop.
d. current comes from a battery.
e. A magnetic field is always created around the wire.
____ 10. A wire carrying a current is bent into a loop. The magnetic field is strongest
a. at the center of the loop.
b. at the edges of the loop.
c. where the loop is located.
____ 11. Magnetic field lines surrounding a magnet are conventionally drawn
a. from south to north.
b. from north to south.
c. either way.
____ 12. Which pairs of objects experiences an attractive force?
a.
b.
A and B
B and D
c.
d.
A and C
B and D
____ 13. In which direction should the magnetic field lines in the picture below be pointing?
a.
b.
From North to South
From South to North
c.
d.
From East to West
From West to East
____ 14. The magnetic field strength inside a current-carrying coil will be larger if the coil is wound around a(n):
a. vacuum.
c. glass rod.
b. wooden rod.
d. iron rod.
2
Name: ________________________
ID: A
____ 15. Three ways you can increase the strength of an electromagnet are ____, ____ and add iron to the core.
a. decrease the number of coils, increase
c. increase the number of coils, decrease
the current
the current
b. increase the number of coils, increase the d. decrease the number of coils, decrease
current
the current
____ 16. The magnetic field is strongest for a wire carrying electric current that has been looped into a coil:
a. inside the coil.
c. far away from the coil.
b. outside the coil.
d. everywhere.
____ 17. A proton enters a magnetic field as shown below. What direction does the proton move?
a.
b.
Up
Down
c.
d.
Left
Right
____ 18. An electron enters the magnetic field, as shown below. Describe the direction of the force that the electron
feels.
a.
b.
Out of the Page
Into the Page
c.
d.
Right
Left
____ 19. An electron (q = 1.6 x 10 −19 C ) is moving at 5000 m/s perpendicular to a 20 T magnetic. How much force
acts on the electron? (Use F = Bqv )
a. 1.6 x 10 -10 N
c. 1.6 x 10 -14 N
-17
b. 1.6 x 10 N
d. 1.6 x 10 -5 N
3
Name: ________________________
ID: A
____ 20. A wire carries current into the page as shown below. What is the direction of the magnetic field?
a.
b.
Clockwise Around the Wire
Counter Clockwise Around the Wire
c.
d.
Into the Page
Out of the Page
____ 21. A 2.0 m length of wire carrying a 20.0 A current is placed in a horizontal magnetic field of 2.0 x 10-3 T.
What is the force acting on the wire? (Use F = BIL )
a. 0.05 N
c. 55 N
b. 0.08 N
d. 0.04 N
Multiple Response
Identify one or more choices that best complete the statement or answer the question.
____ 22. Which of the following creates a magnetic field? MARK ALL THAT APPLY.
a. A metal ball with 2 coulombs of static
c. A coil of wire carrying current
charge on it
b. A piece of aluminum
d. An atom of iron.
Problem
23. A step-up transformer has 40 turns on its primary and 100 turns on its secondary. When the primary is
supplied with an alternating current at 140 V, what is the voltage across the secondary?
4
ID: A
Magnetism
Answer Section
MULTIPLE CHOICE
1. ANS:
KEY:
2. ANS:
OBJ:
KEY:
3. ANS:
KEY:
4. ANS:
STA:
5. ANS:
STA:
6. ANS:
KEY:
7. ANS:
KEY:
8. ANS:
STA:
BLM:
9. ANS:
OBJ:
BLM:
10. ANS:
OBJ:
BLM:
11. ANS:
STA:
BLM:
12. ANS:
13. ANS:
14. ANS:
15. ANS:
16. ANS:
17. ANS:
18. ANS:
19. ANS:
20. ANS:
21. ANS:
C
PTS: 1
DIF:
induce | current
BLM:
A
PTS: 1
DIF:
37.3 Generators and Alternating Current
electrical | mechanical
BLM:
A
PTS: 1
DIF:
magnet | coil | speed
BLM:
C
PTS: 1
DIF:
P4.2B
KEY: transformer | magnet
B
PTS: 1
DIF:
P4.2B
KEY: transformer | voltage
D
PTS: 1
DIF:
faraday's law | induction | voltage
BLM:
A
PTS: 1
DIF:
half | magnet BLM: knowledge
A
PTS: 1
DIF:
P3.p8 | P3.p8A
KEY:
comprehension
E
PTS: 1
DIF:
36.5 Electric Currents and Magnetic Fields
comprehension
A
PTS: 1
DIF:
36.5 Electric Currents and Magnetic Fields
analysis
B
PTS: 1
DIF:
P3.p8 | P3.p8A
KEY:
knowledge
B
PTS: 1
A
PTS: 1
D
PTS: 1
B
PTS: 1
A
PTS: 1
B
PTS: 1
B
PTS: 1
C
PTS: 1
A
PTS: 1
B
PTS: 1
1
L2
OBJ:
comprehension
L1
STA:
knowledge
L2
OBJ:
comprehension
L2
OBJ:
BLM:
L2
OBJ:
BLM:
L1
OBJ:
knowledge
L1
OBJ:
37.1 Electromagnetic Induction
P4.2B | P4.10A
37.1 Electromagnetic Induction
37.5 Transformers
comprehension
37.5 Transformers
application
37.2 Faraday's Law
36.1 Magnetic Poles
L2
OBJ: 36.2 Magnetic Fields
compass | magnet
L2
KEY: current | wire | magnetic
L2
KEY: wire | current | lop
L1
OBJ: 36.2 Magnetic Fields
field | magnet | draw
ID: A
MULTIPLE RESPONSE
22. ANS: A, C
Any moving charge creates a magnetic field.
PTS: 1
PROBLEM
23. ANS:
350 V
PTS: 1
STA: P4.2B
DIF: L2
OBJ: 37.5 Transformers
KEY: transformer | turns
BLM: application
2