# Practice Test - Magnetism & Inductance

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16 Νοε 2013 (πριν από 3 χρόνια και 7 μήνες)

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Practice Test
-

Magnetism & Inductance

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.

The principal reason voltage is induced in the
loops of a generator coil is that the

a.

loops are rotating, changing the amount of
magnetic field within the loops.

b.

size

of the loops is changing.

c.

magnet's strength is changing.

d.

magnet is rotating.

e.

all of the above

3.

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.

4.

A transformer transforms

a.

magnetic field lines.

b.

generators into motors.

c.

voltage.

d.

unsafe

forms of energy into safe forms.

5.

If a transformer increases AC voltage, it will also
increase

a.

energy.

b.

magnetic field strength.

c.

power.

d.

current.

e.

none of the above

6.

Cross
-
country power lines carry voltages of about

a.

60 V.

b.

120 V.

c.

2200 V.

d.

120,000 V.

7.

You are trying to design a motor for a hair dryer
manufacturer. For the motor to work properly, a
wire must be deflected upward. Which of the
following principles could be used to produce this
motor effect?

a.

Moving charges experience a force that is
perpendicular to both their motion and the
electric field they traverse.

b.

Moving charges experience a force that is
parallel to both their motion and the electric
field they traverse.

c.

Moving charges
experience a force that is
perpendicular to both their motion and the
magnetic field they traverse.

d.

Moving charges experience a force that is
parallel to both their motion and the magnetic
field they traverse.

8.

Which of the following is NOT true
of
electromagnetic waves?

a.

An electric field is created in any region of
space in which a magnetic field is changing
with time.

b.

A magnetic field is created in any region of
space in which an electric field is changing
with time.

c.

Induction of
electric fields by changing
magnetic fields occurs only if a conducting
material is present.

d.

Induction of magnetic fields by changing
magnetic fields occurs even in the absence of
a conducting material.

9.

If the north pole of one magnet is brought

near
the south pole of another magnet, the poles will

a.

repel each other.

b.

attract each other.

c.

not interact with each other at all.

10.

Magnetic domains are

a.

regions that may or may not be magnetized.

b.

clusters

of atoms randomly aligned.

c.

regions of atoms magnetically aligned.

d.

blocks of material.

11.

Permanent magnets can be made by

a.

placing a piece of iron near a strong
electromagnet.

b.

placing a piece of iron in a strong magnetic
field.

c.

stroking material containing iron with a
magnet.

d.

all of the above

e.

none of the above

12.

In order to make an electromagnet, you need a

a.

battery, a nail, and a magnet.

b.

battery, some wire, and a nail.

c.

loop

of wire, contacts, and a battery.

d.

magnet, a nail, and some wires.

e.

none of the above

13.

A galvanometer can also be made into

a.

an ammeter.

b.

a voltmeter.

c.

both A and B

d.

none of the above

14.

Which pole of a compass needle points
to a south
pole of a magnet?

a.

south pole

b.

north pole

c.

both A and B

15.

If a compass is moved from the Northern
Hemisphere to the Southern Hemisphere, its
magnetic needle will change direction

a.

not at all.

b.

by 90 degrees.

c.

by

180 degrees.

d.

none of the above

True/False

Indicate whether the statement is true or false.

16.

Underlying the operation of an electric motor is a
current
-
carrying wire that is rotated when in a
magnetic field.

17.

Because magnetism is slightly different from
electrostatics, magnetic fields do not exist.

18.

Spinning electrons themselves are small magnets.

19.

Magnetic domains are regions in a material where
clusters of atoms are randomly magnetized.

20.

A current
-
carrying wire experiences a force when
the wire is perpendicular to a magnetic field.

Practice Test
-

Magnetism & Inductance

MULTIPLE CHOICE

1.

ANS:

C

PTS:

1

DIF:

L2

OBJ:

37.1 Electromagnetic Induction

STA:

Ph.5.a

KEY:

induce | current

BLM:

comprehension

2.

ANS:

A

PTS:

1

DIF:

L2

OBJ:

37.3 Generators and Alternating Current

STA:

Ph.5.g | Ph.5.h

KEY:

volt | generator | magnet

BLM:

analysis

3.

ANS:

C

PTS:

1

DIF:

L2

OBJ:

37.5 Transformers

STA:

Ph.5.a
| Ph.5.b

KEY:

transformer | magnet

BLM:

comprehension

4.

ANS:

C

PTS:

1

DIF:

L2

OBJ:

37.5 Transformers

STA:

Ph.5.a | Ph.5.b

KEY:

transformer | voltage

BLM:

comprehension

5.

ANS:

E

PTS:

1

DIF:

L2

OBJ:

37.5 Transformers

STA:

Ph.5.a | Ph.5.b

KEY:

voltage | transformer

BLM:

comprehension

6.

ANS:

D

PTS:

1

DIF:

L1

OBJ:

37.6 Power Transmission

STA:

Ph.5.a | Ph.5.b

KEY:

voltage | power lines

BLM:

knowledge

7.

ANS:

C

PTS:

1

DIF:

L2

OBJ:

37.4 Motor and Generator Comparison

KEY:

motor | motor
effect

BLM:

application

8.

ANS:

C

PTS:

1

DIF:

L2

OBJ:

37.7 Electromagnetic Waves

KEY:

induction | electromagnetic induction

BLM:

knowledge

9.

ANS:

B

PTS:

1

DIF:

L1

OBJ:

36.1 Magnetic Poles

STA:

Ph.5.e | Ph.5.f | CA.IE.1i

KEY:

south | north | magnet

B
LM:

knowledge

10.

ANS:

C

PTS:

1

DIF:

L1

OBJ:

36.4 Magnetic Domains

STA:

Ph.5.f

KEY:

domain | magnet

BLM:

knowledge

11.

ANS:

D

PTS:

1

DIF:

L2

OBJ:

36.4 Magnetic Domains

STA:

Ph.5.f

KEY:

permanent | magnet

BLM:

comprehension

12.

ANS:

B

PTS:

1

DIF:

L1

OBJ:

36.5 Electric Currents and Magnetic Fields

STA:

Ph.5.g

KEY:

electromagnet | wire

BLM:

knowledge

13.

ANS:

C

PTS:

1

DIF:

L1

OBJ:

36.8 Meters to Motors

STA:

Ph.5.k

KEY:

galvanometer | ammeter | volt

BLM:

knowledge

14.

ANS:

B

PTS:

1

DIF:

L1

OBJ:

3
6.2 Magnetic Fields

STA:

Ph.5.f | CA.IE.1i

KEY:

compass | south

BLM:

knowledge

15.

ANS:

A

PTS:

1

DIF:

L2

OBJ:

36.2 Magnetic Fields

STA:

Ph.5.f | CA.IE.1i

KEY:

compass | hemisphere | north

BLM:

comprehension

TRUE/FALSE

16.

ANS:

T

PTS:

1

DIF:

L2

OBJ:

37.3 Generators and Alternating Current

STA:

Ph.5.g | Ph.5.h

KEY:

motor | current | rotate

BLM:

comprehension

17.

ANS:

F

PTS:

1

DIF:

L2

OBJ:

36.3 The Nature of a Magnetic Field

STA:

Ph.5.e | Ph.5.f

KEY:

magnet | electrostatic

BLM:

comprehension

18.

ANS:

T

PTS:

1

DIF:

L1

OBJ:

36.3 The Nature of a Magnetic Field

STA:

Ph.5.e | Ph.5.f

KEY:

electron | spin

BLM:

knowledge

19.

ANS:

F

PTS:

1

DIF:

L1

OBJ:

36.4 Magnetic Domains

STA:

Ph.5.f

KEY:

domain | cluster | magnet

BLM:

knowled
ge

20.

ANS:

T

PTS:

1

DIF:

L2

OBJ:

36.7 Magnetic Forces on Current
-
Carrying Wires

KEY:

wire | force | perpendicular

BLM:

comprehension