2-9.
Which of the following actions is
NOT a function provided by
switchboards aboard ships?
1.
Automatic shifting of power to
alternate sources if normal
power is lost
2.
Distribution of three-phase,
450 volt power
3.
Circuit protection
4.
Control, monitoring, protection
of the ship’s service
generators
2-10.
What is the purpose of disconnect
2-11.
2-12.
2-13.
2-14.
links?
1. They provide a convenient means
of load testing
2.
They provide isolation from one
switchboard while repairs are
being conducted on another
3.
They provide a means of
securing switchboard power in
case of fire
4.
They provide over current
protection to the main bus
The output of all ac generators is
developed in what part of the
generator?
1.
The field windings
2. The stator windings
3. The rotor windings
4.
The armature windings
What are the two major assemblies
of an ac generator?
1.
Stator and rotor
2.
Stator and armature
3.
Armature and rotor
4.
Armature and fields
Three-phase generators have single-
phase windings located what number
of degrees out of phase from the
other windings?
1.
90° out of phase with the other
two windings
2.
120° out of phase with the
other two windings
3.
180° out of phase with the
other two windings
4.
360° out of phase with the
other two windings
The three-phase, four-wire, STAR
connected power distribution system
is also know by what other term?
1.
Delta connected
2.
Ana connected
3.
Wye connected
4. Jal connected
2-15.
In a transformer, electrical energy
is transferred from one circuit to
another through which of the
following actions?
1.
Hysteresis coupling
2. Electrostatic radiation
3. Electromagnetic induction
4.
Inductive reactance
2-16.
Energy in a transformer is always
transferred without a change in
frequency, but you can expect a
change in which of the following
attributes?
1. Amplitude and time
2.
Inductance and current
3.
Current and voltage
4.
Voltage and inductance
2-17.
Which transformer winding is
designated as the primary winding?
1.
The one that receives energy
from an ac source
2.
The one with the highest
voltage
3.
The one with the lowest voltage
4.
The one that delivers energy to
the load
2-18.
What are the two principle types of
transformers?
1. Core and shell
2.
primary and secondary
3.
Single-phase and polyphase
4.
Ac and dc
2-19.
Most power supply transformers are
designed to operate at frequencies
of
1.
50 to 60 HZ
2.
60 to 120 Hz
3.
120 to 220 Hz
4.
220 to 400 Hz
2-20.
Transformers of higher frequencies
are of smaller design and permit
savings of weight and use of
associated equipments.
1.
True
2.
False
2-21.
The use of varnish to insulate
adjacent laminations in a
transformer core helps minimize
which of the following factors?
1.
Heat dissipation to the
enclosure
2.
Hysteresis losses
3.
Magnetization of the secondary
winding
4.
Magnetization of the primary
winding
9
