記憶度
15問
35問
0問
0問
0問
アカウント登録して、解答結果を保存しよう
問題一覧
1
A PERMEABLE (NATATAGUSAN) SUBSTANCE IS ONE
through which the magnetic lines of force can pass very easily
2
the customer is only charged or credited as the case may be, for the difference between the electricity supplied by the distribution utility and electricity it supplies to the distribution utility when the times it has excess VRE generation both of which are using either 2 unidirectional meters one for import and for export or a single bidirectional meter
Net Metering
3
Electric Field lines are close together where the field is large
true
4
If a tropical storm is going to the Philippine Area of Responsibility within 24 hours what type of alert is to be raised in accordance with the Philippine Grid Code
Blue Alert
5
for any circuit the number of independent equations containing emfs resistances and currents equals the number of ______
branches
6
In the context of the loop and junctions rules for electrical circuits a junction is where_____
three or more wires are joined
7
which of the following statement is false
windows 98 is RTOS
8
Determine the GMR of a three-equal strands conductors in vertical formation in terms of r of an individual strand
1.7036 r
9
A cylindrical copper rod has resistance R. It is reformed to twice its original length with no change in volume. What is its new resistance?
4R
10
DMC stands for? created by ERC in compliance to PDC
Distribution Management Committee
11
the rms value value of ac current is
that steady current that produces the same rate of heating in resistor as the actual current.
12
it refers to the powerloss due to alternating magnetization and demagnetization of the core material
hysterisis loss
13
Which of the following is the following is the correct statement about coulomb?
the amount of charge that flows a past point in one second when the current is one ampere
14
When a dc motor has no load, what will happen to the back emf?
becomes maximum
15
synchronizing power of a synchronous machine is
inversely proportional to the synchronous reactance
16
It is a device which functions on failure of a machine, transformer or of other apparatus to ground or on flash over of a dc machine to ground
ground protective relay
17
the total load on any overcurrent device located in a panelboard shall not exceed ___ of its rating where the normal operation the load will continue for three hours or more
80%
18
the region or area in a transistor that is heavily doped
emitter
19
GMC was created by the Energy Regulatory Commision to monitor the compliance of the users of the Grid to the PGC. What does the GMC stands for?
Grid Management Committee
20
It is possible to increase the field flux and, at the same time, increase the speed of a dc motor provided its _______ is held constant
Armature current
21
It is considered as the heart of a dc machine
Armature winding
22
While describing the shealth of a cable, the abbreviation XLPE means _____________ polyethylene
cross-linked
23
Conductors supplying two or more motors shall have an ampacity equal to the sum of the following current rating of all the motors plus ______% of the highest rated motor in the group
25
24
Megger essentially is a
megohmmeter
25
Which of the following cannot have a single unit of 100 MW
Diesel power plant
26
Chemicals with lower flash points presents a greater ______
Flammability hazard
27
What is the maximum number of conductors in a raceway that does not need to be derated
3
28
Which of the following type of fault used only the equivalent positive sequence impedance of the circuit in the short circuit calculation
Three phase fault
29
Which of the following insulators will be selected for high voltage application
Suspension type
30
Base load plants are designed to supply power at
high capital cost and low operating cost
31
Which is not a characteristics of an ideal transformer
finite permeability
32
What is the IEEE device function number 50
Instantaneous overcurrent relay
33
Transformer breaths in when
load on it decreases
34
The color reserved for use in equipment grounding conductor is
Green
35
Joule found out that the heat produced in a current carrying conductor is proportional to
the square of the current
36
The applied voltage in a transformer is increased by 50% and frequency is reduced by 50%. The maximum core flux density will become
3 times
37
A battery is used to change a parallel plate capacitor, after which it is disconnected.Then the plates are pulled apart to twice their original separation. This process will double the :
Stored energy
38
A step-down transformer is used to
decrease the voltage
39
Iron, rather than copper, is used in the core of transformers because iron:
has a very high permeability
40
The tesla is a unit of
magnetic flux density
41
Which of the following statements regarding the motion of a conductor through a changing magnetic field is FALSE
The conductor must move at constant velocity in order to generate a current
42
A DC system can be protected from lightning by including a thyrite tube in the circuit that connects the high voltage line with the ground. Which of the following is FALSE regarding a thyrite tube?
Its fusable link melts at high voltages
43
Which of the following statements regarding transformer is FALSE
One three phase transformer weighs more than three equivalent single phase transformer
44
For an existing a.c. transmission line the string efficiency is 80%. Now if d.c voltage is supplied for the same set up, the string efficiency will be:
100%
45
The inductance per unit length of an overhead line due to internal flux linkages
Is independent of the size of conductor and constant
46
High permittivity ceramic is used for capacitors of
A few uF to a few hundred uF
47
What are the causes of gross error in the instrument 1. Misreading of instruments 2. Incorrect adjustment of instruments 3.Errors due to defective instruments 4.Errors due to effort of environment on the instrument
1 and 2
48
The phase shift between the current and voltage vectors is due to the following except one
electric flat iron
49
An aternating voltage is given by v=100 sin 314t volts. Its average value will be
63.7 V
50
It is desired to have a constant direct current i(t) through the ideal inductor L. The nature of the voltage source v(t) must
an ideal impulse
51
The ordinary efficiency of a given transformer is maximum when
its Cu loss equals iron loss
52
Receptacles installed on 15- and 20- ampere branch circuits must always be of what type
Grounding type
53
In a circuit breaker the time duration from the instant of energizing of the trip coil is known as
protection time
54
Over voltage protection is recommended for
All of these
55
What is the fourth harmonic of 800 KHZ
3.20 MHZ
56
The fuse used for the overhead primary distributors is
expulsion
57
Peak load plants are designed to supply power at
low capital cost and high operating cost
58
Which of the following principle will the operation of fiber optic cable is based
reflection
59
In a wye connected system, line current is
equal to the phase current
60
A device that establishes an electrical connection to the earth
Grounding electrode
61
What determines the direction of force in a conductor
Left hand rule
62
In a parallel circuit, the potential difference across the resistance
is always constant
63
Based on the Philippine Distribution code (PDC), the Distributor may establish penalties for Users whose power factors are less than
85%
64
An Act to ensure and accelerate the total electrification of the Philippines, also known as EPIRA law of 2001
RA 9136
65
If we increase field current of a dc generator, its emf output
increases till the magnetic saturation takes place
66
Armature reaction in an alternator primarily affects
generated voltage per phase
67
What is the equivalent of the collector terminal of transistor in a FET
Drain
68
Branch circuit conductors supplying a single motor shall have an ampacity NOT less than _____ percent of the motor full load current rating
125
69
Ten oersted is equivalent to
0.1cm/GB
70
The transients which are produced due to sudden but energetic changes from one steady state of a circuit to another are called
Transition
71
The relative polarity of the winding of a transformer may be determined by
phasing out
72
When luminaires direct 90 to 100% of their output upward is considered a
Indirect lighting
73
Which of the following limits the number of coils that may be placed on the armature of a DC motor or generator
coil to coil arcing due to the breakdown of insulation
74
A transformer has negative voltage regulation when its power factor is
leading
75
When a step input is applied to a second order circuit, the final values of the circuit variables are found by
Replacing capacitors with open circuits and inductors with closed circuits
76
Power factor can be improved by connecting which among these
Static capacitors and synchronous condensers
77
Which of the following is NOT a reason why single-phase induction motor run
hysteresis
78
What is the device function number of overvoltage relay
59
79
"Debye" is the unit of
Electric dipole moment
80
Relay used for feeder protection is
translay relay
81
Electric hazards include shock, electric arcs and blasts and ____ or faulty equipment
Broken
82
The resistance of a semiconductor is known as
bulk resistance
83
What does the fourth loop of an electronic resistor color code represent
Tolerance
84
Auxiliary gutters shall not contain more than ______ current carrying conductors at any cross section
30
85
In the list below, which ine is not a type of present day nuclear power plant
fussion fission reactor
86
The ratio of the average load on the plant for the period of time considered to the aggregate rating of all the generating equipment
Capacity factor
87
In an ideal transformer
All of these
88
The full load copper loss in a transformer is 400 watts. At half load, the copper loss will be
100 watts
89
In a HRC fuse the time between cut-off and final current zero, is known as
arcing time
90
The advantage of the ring main system is
Continuity of supply to feeding points
91
When the stator windings are connected in such a fashion that the number of poles are made half, the speed of the rotor of a synchronous motor
increases to two times the original value
92
The imaginary or fictitious part of synchronous reactance takes care of
armature reaction
93
The electrical analog of a spring constant k is:
1/C
94
A 2-uF and a 1-uF capacitor are connected in series and a potential difference is applied across the combination. The 2 -uF capacitor has
half the potential difference of the 1-uF capacitor
95
A "coulomb" is
the amount of charge that flows past a point in one second when the current is 1 A
96
The tesla is a unit of
magnetic flux density
97
Induction generators deliver power at
Leading power factor only
98
The wire with the highest temperature rating is
THHN
99
As substance that changes it electrical resistance when illuminated by light is called
Photoconductive