CH.81
The most common measurement made with a
meter is:
A )
amperage
B )
watts
C )
resistance
D ) voltage
E )
capacitance
When reading the dials of a power meter,
read:
A )
them in the sequence shown by the letters under each
B )
them from left to right
C )
the ones which rotate clockwise first
D ) them from right to left
E )
them only at the request of the utility company
The instrument used to measure electrical
power used in a period of time, is the:
A ) kilowatt hour meter
B )
voltmeter
C )
ohm meter
D )
milliamp meter
E )
oscilloscope
A clamp-on ammeter measures current flow by
using:
A )
differential voltage
B )
differential current flow between two conductors
C ) a basic transformer
principle
D )
a portion of circuit resistance
E )
a portion of circuit resistance
Clamp-on ammeter readings may be inaccurate
if:
A ) jaws are dirty or
misaligned
B )
circuit voltage is too high
C )
circuit resistance is too low
D )
circuit power is too high
E )
conductor insulation is too thick
When using an electrical meter to check
that a circuit is safe to work on, it is important to verify the proper scale,
current, or both that is being used because:
A ) it may appear that no
voltage or current is present and therefore safe
B )
the meter will be damaged
C )
the user will be subjecting himself or herself to danger
D )
the main high voltage transformer circuit will be opened
E )
electrical wiring will be damaged by fire or overheating
Batteries:
A )
do not pose any immediate electrical hazards
B )
produce a steady AC voltage
C )
produce a varying DC voltage
D ) produce a steady DC
voltage
E )
produce a varying AC voltage
Ammeters are connected with the negative or
black lead connected to the:
A )
positive side of the circuit
B )
north pole of the circuit
C ) negative side of the
circuit
D )
switch of the circuit
E )
neutral wire of the circuit
The black demand pointer of a power meter:
A )
moves the red pointer
B )
always reads the current demand
C )
resets automatically
D )
indicates the amperage being drawn
E ) must be manually reset
A power meter:
A )
reads the actual power consumed
B )
does not require a multiplying factor
C ) reads only a small
percentage of the actual load
D )
will calculate the actual cost of the power
E )
does not take into account the system voltage
CH.82
A compound wound DC generator may have
three characteristics which are a:1. decreasing output voltage versus load2. no
amperage requirement 3. constant output voltage 4. supplementary AC requirement 5.
rising output voltage versus load
A )
1, 2, 4
B )
2, 3, 5
C ) 1, 3, 5
D )
1, 4, 5
E )
2, 3, 4
Three types of DC motors are shunt, series
and
A )
reverse wound
B )
armature
C )
stator
D ) compound
E )
cross compound
The connection provided on DC motors to
supply the armature with power:
A )
are slip rings
B )
are field poles
C )
is a rheostat
D ) is a commutator
E )
is a rotating conductor
A 6 pole alternator producing 60 Hz power
must turn at:
A )
1800 rpm
B )
2400 rpm
C )
1000 rpm
D ) 1200 rpm
E )
600 rpm
The field strength of an alternator may be
changed by varying the amplitude of the DC power, supplied to the rotating
field by:1. the use of a field rheostat2. a reducing gear3. changes of the
input frequency4. electronic control
A )
1, 2, 3
B ) 1, 4
C )
1, 3, 4
D )
2, 3, 4
E )
3, 4
Alternators must run at constant speed in
order to maintain:
A )
current
B )
power
C )
voltage
D )
resistance
E ) frequency
The ________________________ of a DC
machine is built up of laminated steel plates mounted on the shaft. The coils
are connected to a commutator mounted on one end of the rotor shaft.
A ) armature
B )
yoke
C )
bearings
D )
coils
E )
rheostat
In order to produce the strength of
magnetic flux required in larger DC machines:
A ) electromagnets are used
B )
copper switches are used
C )
permanent magnets are used
D )
the field windings are double wound
E )
booster transformers are used
A rheostat is used to __________ the field
strength in a DC machine.
A )
stop
B )
make
C )
heat
D ) vary
E )
remove
A rheostat is also known as a:
A )
voltage regulator
B )
resistance regulator
C )
current controller
D ) variable resistor
E )
flux field regulator
CH.83
A transformer works on the principle of:
A )
reverse polarity
B ) magnetic induction
C )
DC power flowing in one direction
D )
straight polarity
E )
automatic induction
Current transformers step down the current
rather than the:
A )
resistance
B )
flux strength
C )
conductance
D )
number of poles
E ) voltage
If E p / Es = Np / Ns then Ns will equal:
A )
E p/ Np Es
B )
E p Es / Np
C )
Np EsE p
D )
Np E p / Es
E ) NpEs / E p
The capacity of a transformer can be
increased by:1. submerging the core and windings in a tank of oil2. submerging
the core and windings in a tank of water3. forced air cooling the oil in a heat
exchanger 4. wrapping the core with a thermal insulation 5. forced air cooling of
the core
A ) 1, 3, 5
B )
2, 3, 4
C )
1, 4, 5
D )
2, 3, 4, 5
E )
2, 4, 5
A transformer has a primary voltage of 500
volts and 20 turns on the primary winding. If the secondary winding has 5 turns
the voltage of the secondary is:
A )
2000 volts
B )
2500 volts
C ) 125 volts
D )
100 volts
E )
4 volts
When AC action causes a counter current in
a coil it is termed:
A ) self inductance
B )
capacitance
C )
hysteresis
D )
current generation
E )
electromagnetic induction
A phenomena produced by electronic
switchgear which can result in excessively high voltages in transformers are
known as:
A )
capacitive reactance
B )
inductive reactance
C )
phase lag
D )
reactive voltage losses
E ) harmonic distortion
Transformers are rated in terms of:1. Volt
amperes 2. Kilowatts3. Kilovolt amperes 4. Ohms
A )
1, 2
B )
2, 4
C )
2, 3
D )
3, 4
E ) 1, 3
When magnetic flux produced by one coil
induces an EMF in a second coil it is called:
A )
self inductance
B )
electromagnetic induction
C ) mutual inductance
D )
capacitive reactance
E )
inductive reactance
Transformer cooling oil has:
A ) a very high specific heat
B )
a poorer insulating characteristic than air
C )
a very high fire point
D )
no factors which necessitate better wire insulation
E )
a very low safety hazard
CH.84
The best type of diagram for showing supply
and distribution systems is the:
A )
riser diagram
B ) one-line diagram
C )
elementary diagram
D )
connection diagram
E )
terminal and connection diagram
A typical extra low voltage device would be
a:
A )
toaster
B )
set of tree lights
C ) door bell
D )
dry cell battery charger
E )
night light
Low voltage systems may have an acceptable
voltage variation of plus or minus:
A )
10%
B ) 5%
C )
1.5%
D )
7.5%
E )
12.5%
An electrical distribution system is
composed of service, feeders and:
A )
secondary circuits
B )
primary circuits
C ) branch circuits
D )
trunk circuits
E )
tertiary circuits
The ability of an electrical circuit to
store a charge of electricity even after the circuit is opened is termed:
A )
hysteresis
B )
grounding
C )
inductance
D )
reactance
E ) capacitance
The utility's responsibility will not go
beyond the:
A )
first branch line
B ) first over current device
C )
primary transformer
D )
first trunk circuit
E )
motor control centre
When working with high voltage systems, the
minimum distance of approach should be:
A )
1 metre
B )
5 metres
C ) 2 metres
D )
3 metres
E )
0.5 metres
A prime factor in determining the voltage
to be used in a circuit is:
A )
transformer capacity
B )
peak demands
C ) degree of access to
equipment
D )
the number of motors involved
E )
the resistance of the circuit
CH.85
A prime factor in determining the voltage
to be used in a circuit is:
A ) transformer capacity
B )
peak demands
C )
degree of access to equipment
D )
the number of motors involved
E )
the resistance of the circuit
A control device which will change one form
of energy into another form of energy is the:
A )
controller
B )
logic device
C )
primary element
D ) transducer
E )
transmitter
In a "closed loop" system of
control, the control will change:
A ) automatically
B )
both automatically and manually
C )
manually
D )
intermittently
E )
inversely to the signal
Five common medium used to implement
process control includes mechanical, pneumatic, electrical, analog, and:
A )
liquid
B )
solid
C )
hydraulic
D ) digital
E )
fibre optics
1 PSI equals:
A )
1 kilopascal
B ) 6.89 kPa
C )
100 kPa
D )
1 newton per metre squared
E )
1 kilogram per metre squared
A device which will cause a visible light
signal to become an instrument analog signal is the:
A ) photoelectric transducer
B )
transmitter
C )
controller
D )
final element
E )
current-to-pneumatic transducer
A sensing element receives its signal from
the:
A )
controller
B )
recorder
C )
control valve
D )
transducer
E ) transmitter
The major elements needed to construct
automatic control loop instrumentation systems includes a sensing element, a
__________________, a controller and a control valve.
A )
recorder
B )
resistance
C ) transmitter
D )
manometer
E )
float cage
The apparatus which converts current
signals to pneumatic and pneumatic to current signals is called a:
A )
converter
B )
inducer
C )
inverter
D ) transducer
E )
transformer
When a process variable has no method of
sending information to the final control element the system is known as:
A )
an automatic system
B ) an open loop system
C )
a cascading system
D )
feedback system
E )
feed forward system
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