WorksheetsEE-PREBOARD MULTIPLE CHOICES
Total questions: 47
Worksheet time: 24mins
An initially uncharged capacitor C is connected in series with resistor R. This combination is then connected to a battery of emf V₀. Sufficient time elapses so that a steady state is reached. Which of the following statements is NOT true?
The total thermal energy generated by R is independent of R
The total thermal energy generated by R is independent of Vo
The final charge on C is independent of R
The time constant is independent of Vo
An alternator running in parallel with the other alternators all having automatic voltage regulators is to be taken off the bus. The usual procedure before opening the switch is to ______.
reduce the power fed to the prime mover
reduce alternator excitation
do nothing
increase alternator excitaiton
Which gas is formed near to the conductors by producing a hissing noise?
ozone
nitrogen
oxygen
hydrogen
Which photometer is used for comparing the lights of different colors?
Guilds Flicker Photometer
Grease spot Photometer
Bunson photometer
Lummer Brodhum Photometer
Which one does not belong to the technical performance standards of the Philippine Distribution Code?
Collection efficiency
Plant efficiency
load distribution
reliability
Which of the following shall be included in the calculation of the reliability standard indices of the distributor asset by the Philippine Distribution Code?
Outages that occur on the primary lines of the distribution system
Planned outages where the customers have been notified at least three (3) days prior to the loss of power
outages that occur in he transmission line
Outages that occur on the secondary lines of the distribution system
A mode of communications in which either party can hear while talking, thus allowing one party to instantly interrupt the other at any time, is called _____.
Full duplex
Half duplex
full simplex
half simplex
The overcurrent protective device is caused to operate by _____.
current flow
voltage surge
impedance
voltage drop
The distinguishing characteristic of this configuration of a system is that it cannot compensate for any disturbances that add to the controller`s driving signal.
open-loop systems
closed-loop systems
disturbance configuration
transducer configuration
Which of the following is an example of a load with leading power factor?
synchronous motors
water heaters
incandescent lamp
doorbells
A control system consists of subsystems and __________ assembled for the purpose of obtaining a desired output with desired performance, given a specified input.
processes
systems
subsystems
subprocesses
What is the type of relay that is intended to respond to the difference between incoming and outgoing quantities?
Differential
Directional
Subtractive
Distance
Instrument transformers are used in indicating and metering and with protective devices, they are used for _____.
relaying
detecting
measuring
sensing
If low head and large quantity of water are available, a power engineer should select:
Kaplan turbine
Francis Turbine
none of the choices
Pelton Turbine
If the reference bus is changed in two load-flow runs with the same system data and power obtained for reference bus taken as specified P and Q in the latter run,
the system losses will be unchanged but complex bus voltages will change
the system losses will be change but complex bus voltages remains unchanged
the system losses as well as complex bus voltage will change
the system losses as well as complex bus voltage will unchange
The strain type insulators used when:
The transmission line is dead ended and the direction of transmission line changes.
The transmission line is dead ended.
The transmission line is short.
The direction of transmission line changes.
A golf ball is struck by a golf club and falls on a green three meters above the tee. The potential energy of the Earth-ball system is greatest:
When the ball reaches the highest point in its flight
Just before the ball is struck
When the ball comes to rest on the green
Just after the ball is struck
Which of the following is not a full-duplex?
radar
Telephone
Tolometry
Local Area Network
For equations of motion in resonance, why do we set β = ω when 0.95 < ω/β < 1.05?
In this case, we assume β to be equal exactly to ω.
It is to prevent longer solution.
The above statement are not true.
It is a general requirement.
Tall growing plants refer to plants, vines, and other plant species, which grow or have the potential to grow more than ________ in height from the ground.
3 meters
1 meter
4 meters
2 meters
A diversity factor of 2.5 gives a saving of __________ % in generating equipment.
60
50
25
40
The selection of kAIC rating of circuit breaker is based on _____ current.
Symmetrical fault
Asymmetrical fault
Full-load
Short-load
In a circuit breaker, the time duration from the instant of the fault to the extinction of the arc is known as:
Total clearing time
lag time
operation time
lead time
A magnet moves inside a coil. Consider the following factors:
I. strength of the magnet
II. number of turns in the coil
III. speed at which the magnet moves
Which can affect the emf induced in the coil?
I, II, III
I and II only
II only
I only
A load of 50A must be protected by ____ AT inverse time circuit breaker.
125
80
62.5
250
The transients which are produced due to sudden but energetic changes from one steady-state to another are called ________ transients.
transition
subsidence
relaxation
initiation
What is the advantage of a synchronous motor?
it can be constructed with wider air gaps than induction motors which is an advantage, mechanically.
it gives constant speed from no load to full load
it operates at higher efficiencies
All of the choices
The torque exerted by an electric field on a dipole is:
Perpendicular to both field and dipole moment
parallel to dipole moment and perpendicular to the field
parallel to the field and perpendicular to the dipole moment
parallel to both the field and dipole moment
What does PEMC in EPIRA stand for?
Philippine Electricity Market Corporation
Private Energy Marketing Company
Philippine Energy Market Corporation
Philippine Electricity Market Corporation
In solving spring-mass system, if the response of the position is oscillatory, the arbitrary constant with respect to the cosine term becomes the value of _______.
final position
initial position
initial velocity
final velocity
Which of the following positions will lead to critical damping?
x(t) = 8teˉ¹³ᵗ
x(t) = 8eˉ¹³ᵗ
x(t) = 8eˉ¹³ᵗ cos 13t + 8eˉ¹³ᵗ sin 13t
x(t) = 8 cos 13t + 8 sin 13t
What is the equivalent IEEE device function number for directional power relay?
32
50
21
58
The magnetic torque exerted on a flat current-carrying loop of wire by a uniform magnetic field “B” is _______.
Maximum when the plane of the loop is parallel to “B”
Maximum when the plane of the loop is perpendicular to “B”
independent of the orientation of the loop
dependent on the shape of the loop for fixed loop area
What is an electron volt?
The energy gained by an electron in moving through a potential difference of 1 volt.
the force required to move an electron 1 meter
the force acting on an electron in the field of 1 N/C
the energy needed to move an electron through 1 meter in any electric field.
Transient disturbance is produced in a circuit whenever:
it is shorted
its applied voltage is charged suddenly
it is suddenly connected or disconnected from the supply
All of the choices
What are the two major measures of performance in control system?
transient response and steady-state error
transient result and steady-state command
transient error and steady-state response
transient command and steady-state result
The coulomb force F acts on two charges a distance, r, apart. What is F proportional to?
r21
R
R2
r31
Both physical and nonphysical world contains applications of control system.
true
neither true nor false
false, only physical
false, only nonphysical
The transfer bus scheme has the following characteristics except one. Which one is this?
It allows the disconnection of circuit breaker for maintenance without interrupting the service.
It allows better continuity of service as compared with the single bus.
it is more flexible
it is more costly than that of the single bus system
What does IEMOP stand for?
Independent Electricity Market Operator of the Philippines
Integrated Energy Market Operator of the Philippines
Independent Energy Market Operator of the Philippines
Integrated Electricity Market Operator of the Philippines
It is hereby declared unlawful for any person, whether natural or juridical, public or private, to:
All of the choices
plant or cause to be planted tall growing plants, including plants of whatever kind, variety, or height within the power line corridor
construct or erect any hazardous improvements within the power line corridor
conduct or perform any hazardous activities within the power line corridor 38 kV
What is the rated non-continuous load for 10 square meter show window?
16 kVA
14 kVA
18 kVA
20 kVA
The power factor of an alternator is defined by its _____.
excitation
prime mover
speed
load
The power loss is an important factor for the design of:
Transmission lines
generators
motor
feeders
The speed of dc shunt motor can be controlled:
by changing the field resistance
by inserting a resistor in series with armature circuit
by changing the terminal voltage applied to armature
any of the choices
The purpose of providing dummy coils in a generator is:
To provide mechanical balance for the rotor.
to reduce eddy current losses
to amplify voltage
to enhance flux density
A Scott-Tee connection has higher ratio of utilization that an open-delta connection only when _____.
non-identical transformers are used
load power factor is unity
load power factor is leading
identical transformer are used
