COVER TO COVER Flashcards
(211 cards)
1
Q
What is electricity?
A
Physical phenomenon arising from the existence and interactions of electric charge
2
Q
What does electric current describe?
A
A flow of electric charge through a conductor
3
Q
What is the unit of quantity of electric charge?
A
Coulomb (C)
4
Q
What is the elementary charge (e)?
A
1.602 x 10^-19 C
5
Q
According to Coulomb’s Law, what happens to like charges and opposite charges?
A
Like charges repel; opposite attracts
6
Q
What is electric current defined as?
A
The flow of electric charge
7
Q
What is an alternating current (AC)?
A
A current of varying magnitude and direction
8
Q
What is voltage?
A
Driving force of electrical current between two points
9
Q
What does Ohm’s Law state?
A
The voltage across a conducting material is directly proportional to the current flowing through it with resistance as the constant of proportionality
10
Q
What is the formula for power in electrical circuits?
A
Power (W) = Voltage (V) x Current (I)
11
Q
What is the difference between direct current (DC) and alternating current (AC)?
A
DC has a constant magnitude and flows in one direction; AC varies in magnitude and direction
12
Q
What is the significance of Kirchhoff’s Current Law?
A
States that current flowing into a node must equal current flowing out of it
13
Q
What is an insulator?
A
Materials that resist electric current by providing high resistance
14
Q
What is the purpose of a capacitor?
A
To store electric charge
15
Q
What is inductance?
A
A measure of the ability of a device to store energy in the form of a magnetic field
16
Q
What is the definition of resistance?
A
The physical property of an element that impedes the flow of current
17
Q
Fill in the blank: The unit of resistance is _______.
A
Ohm (Ω)
18
Q
What are the four factors that affect resistance?
A
- Material
- Length
- Cross-sectional area
- Temperature
19
Q
What is the definition of a series circuit?
A
A circuit with only one current path
20
Q
What is a parallel circuit?
A
A circuit with more than one current path branching from the energy source
21
Q
What is an ideal voltage source?
A
A circuit element where the voltage across the source is independent of the current through it
22
Q
What does the power factor (pf) represent?
A
The ratio between real power and apparent power
23
Q
What is reactive power (VAR)?
A
The power that generates the magnetic field required for inductive devices to operate
24
Q
What is the formula for apparent power (VA)?
A
The vector sum of real power and reactive power
25
What is load shedding?
Switching off non-essential loads to maintain uniform load and limit demand
26
What is the purpose of a circuit breaker?
To automatically open a circuit when current exceeds its rating
27
What is a step-down transformer?
A transformer with a secondary voltage less than its primary voltage
28
What is the purpose of overcurrent protection?
To safeguard the building service or an individual circuit from excessive current flows
29
What is electro-magnetism?
The production of voltage in a conductor when moved through a magnetic field
30
What is the definition of a node in electrical circuits?
Connection points for circuit elements
31
What does it mean for current to lag behind voltage in an AC circuit?
The inductive effect causes the phase of the current to lag behind the phase of the voltage
32
What are the properties of a series circuit?
* The same current flows through all resistances
* Voltage drop across each resistance
* The sum of voltage drops equals the applied voltage
33
What are the properties of a parallel circuit?
* Voltage across each resistance is the same
* As many current paths as branches
* Current in each branch follows Ohm’s Law
* Total current equals the sum of branch currents
34
What is the definition of a branch in electrical circuits?
Paths for current to flow and connections between nodes
35
Fill in the blank: Energy charge is the cost of electrical energy _______.
consumed
36
What is the maximum demand in electrical terms?
The user’s highest rate at which energy is consumed in kilowatts
37
What is the demand charge?
The billing fee related to the maximum charge
38
What is the significance of power factor correction?
Reduces load currents, saving hardware costs and avoiding penalties
39
What interrupts the circuit when current exceeds the circuit rating?
Circuit breaker
## Footnote
A circuit breaker can be reset after it trips.
40
What carries power from the transformer through a metering device to the building's service disconnects?
Service entrance
## Footnote
It includes underground or overhead conductors.
41
What is the purpose of a service disconnect?
Allows electrical service from the utility company to be switched off
## Footnote
It consists of fuses or a circuit breaker that protects the service entrance conductors.
42
What type of fuse is cylindrical and available in two types?
Cartridge fuses
## Footnote
Types include ferrule-contact type and knife blade type.
43
What type of fuse can handle an overload for a fraction of a second without blowing?
Time Delay Fuses
## Footnote
These are desirable on circuits serving electric motors.
44
What is the maximum current a conductor can carry without exceeding insulation temperature limits?
Ampacity
## Footnote
Influenced by wire thickness, conductor material, insulation type, and conductor exposure.
45
What happens to the heat output of heating devices with a 10% drop in voltage?
19% decrease in heat output
## Footnote
Appliances work inefficiently on voltages lower than designed.
46
What is a raceway?
An enclosed channel designed for holding wires, cables, or busbars
## Footnote
Examples include conduit, tube, or gutter.
47
What type of conduit is a heavy galvanized steel or aluminum tube?
Rigid Metal Conduit (RMC)
## Footnote
It is smoother than plumbing galvanized steel pipe.
48
What is the function of a generator?
Converts mechanical energy into electrical energy
## Footnote
Requires mechanical torque to turn conductors through a magnetic field.
49
What type of motor can be run on both AC and DC power?
Universal Motor
## Footnote
It has variable speed characteristics with load.
50
What does the term 'Lock Rotor Amperage (LRA)' refer to?
The highest current a motor draws
## Footnote
LRA can be 4 to 6 times the Full Load Amperage (FLA).
51
What is a Variable-Frequency Drive (VFD)?
A solid-state electronic device that controls motor speed
## Footnote
It has variable frequency output.
52
What is a Ground Fault Circuit Interrupter (GFCI)?
A device that detects low leakage current to ground and shuts off power
## Footnote
Types include receptacle outlet type and circuit breaker type.
53
What is the purpose of surge protection devices (SPD)?
Prevents surge from reaching electrical devices
## Footnote
It diverts the surge safely to ground.
54
What is the target voltage entering the service panel called?
System Voltage
## Footnote
It is distributed to the building's service equipment.
55
What type of system uses two wires with one earthed?
Single-Phase, 2-Wire System
## Footnote
This system produces voltage unbalance due to unsymmetrical voltage drop.
56
What type of motor has low starting torque characteristics?
Split-Phase Motor
## Footnote
It is a single-phase induction motor up to 1/3hp.
57
Fill in the blank: The assembly that rotates in a simple AC machine is called the _______.
Rotor
## Footnote
The rotor's delivered power is referred to as the armature.
58
What is the function of brushes in a simple AC machine?
To make the connection to the outside of the machine
## Footnote
Brushes are placed against slip rings.
59
What is the designated full-load power output of a motor called?
Rating or Capacity
## Footnote
Usually measured in horsepower (hp).
60
What indicates the percentage a motor can be continuously overloaded without damage?
Service Factor
## Footnote
For example, 1.20 for 1hp and above.
61
What is the unintentional flow of current from a power source to a grounded surface called?
Ground Fault
## Footnote
It can lead to hazardous conditions.
62
What type of electrical fault is characterized by low and erratic current?
Arc Fault
## Footnote
This includes parallel and series arcing faults.
63
What is the term for the peak instantaneous current drawn when an electrical appliance is first turned on?
In-Rush Current
## Footnote
It can be as high as 100 times the normal current.
64
What protects against lightning strikes with vertical rods placed on structures?
Lightning Protection
## Footnote
It includes a network of conductive tape bonding the rods to grounding electrodes.
65
What are specially designed devices that can withstand explosions within them called?
Explosion-proof Devices
## Footnote
They prevent ignition of specified gases or vapors surrounding the enclosure.
66
What is the primary service voltage for residential utilization?
230V 1PH 2W
## Footnote
Refers to the standard voltage for residential electrical systems.
67
What does the Philippine Electrical Code (PEC) specify?
Minimum provisions necessary for protecting people and property from improper use of electricity and electrical equipment
## Footnote
It consists of rules intended to make electricity use safe.
68
What are mandatory rules in the PEC characterized by?
The word 'shall'
## Footnote
These rules are requirements that must be followed.
69
What is the purpose of an inspection certificate in electrical work?
To certify that an electrical installation has been inspected and is compliant
## Footnote
The certificate of electrical inspection (CEI) is issued by the authority.
70
What is the maximum rating for portable equipment that does not require a permit?
1,200VA
## Footnote
This applies to the installation of electrical portable equipment.
71
What is one objective of the PEC?
Safe use of electricity
## Footnote
This includes establishing basic materials quality and electrical work standards.
72
What is required before undertaking any electrical installation according to the PEC?
A permit
## Footnote
Necessary for compliance with regulations.
73
What type of rules are advisory rules in the PEC characterized by?
The word 'should'
## Footnote
These are recommendations but not mandatory.
74
What should the specification on an electrical plan indicate?
Design compliance with the PEC and other authorities
## Footnote
It should detail the nature of the service, voltage, phase, and frequency.
75
What elements must be included in a title block of electrical plans?
* Name and location of proposed installation
* Name, signature, and address of owner/manager/operator
* Title of sheet and sheet number
* Scale used
* Name, signature and dry seal of professional electrical engineer
* Initial of draftsman
* Date drawn or revised
## Footnote
Title blocks provide essential identification for plans.
76
What is the purpose of grounding in electrical systems?
To protect building occupants and electrical equipment
## Footnote
Grounding involves connecting to an electrode in direct contact with the earth.
77
What is required for system grounding?
Bonding all electrical system components at the service entrance equipment
## Footnote
This includes the neutral bus of the main panelboard or switchboard.
78
What is the definition of a branch circuit?
Portion of a building wiring system that extends beyond the final overcurrent protection device
## Footnote
It includes wiring and one or more outlets.
79
What is the maximum allowable voltage drop from the panelboard to the farthest outlet?
3%
## Footnote
Voltage drop from feeders should not exceed 2%.
80
What color coding is used for ungrounded conductors in single-phase systems?
Black
## Footnote
Grounded conductor is white.
81
What should be done if a short circuit or current overload occurs?
The circuit should be interrupted by a circuit breaker or fuse
## Footnote
This is a protective measure for the circuit.
82
What materials are commonly used for conductors?
* Copper
* Aluminum
## Footnote
These materials are selected based on their conductivity and application.
83
What is the purpose of conductor ampacity adjustment factors?
To account for changes in ambient temperature
## Footnote
This ensures that conductors operate safely within their rated capacity.
84
What is the purpose of an overcurrent protection device?
To protect the wiring in the circuit from excessive current flow.
85
What does an Individual Branch Circuit serve?
Only one receptacle or piece of equipment.
86
What is a General Purpose Branch Circuit?
Supplies two or more outlets for lighting and appliances.
87
What is the maximum current for an Appliance Branch Circuit?
Cannot exceed 20A.
88
What does a Multiwire Branch Circuit consist of?
Two or more ungrounded (hot) conductors having a voltage between them and a common neutral conductor.
89
What is the purpose of a Life Safety Branch Circuit?
To provide adequate power to patients and personnel in emergency systems.
90
What is a Critical Branch Circuit intended for?
To provide power to task illumination and selected receptacles serving areas related to patient care.
91
What must switches be selected to match?
The load they control.
92
What are receptacles selected to match?
The appliance or equipment they serve.
93
What must the overcurrent device be matched to?
The conductor and equipment.
94
What is a Feeder in electrical systems?
A set of conductors that carry a large amount of power from service equipment to a sub-panelboard.
95
What must service entrance equipment be large enough to supply?
The computed load of the building or area being served.
96
What are tamper-resistant receptacle requirements?
Safety measures for preventing accidental electrical shock.
97
What should be considered when designing electrical systems for common spaces?
The number and type of lighting outlets and convenience receptacles.
98
What is a Schematic Diagram?
The simplest representation of an electrical circuit.
99
What does a Lighting Layout show?
The exact position of lighting fixtures, switches, and branch circuit connections.
100
What is the capacity of the Bauang La Union Diesel-Fired Power Plant?
225MW.
101
What type of fuel is used by the Ilijan Combined Cycle Power Plant?
Natural Gas.
102
What are the pros of using fossil fuels?
* Abundant and accessible
* Provide a large amount of concentrated energy
* Cost less
* Can be transported easily
103
What is a disadvantage of fossil fuels?
They are non-renewable.
104
What are the benefits of Combined Heat and Power (CHP)?
* Reduces utility costs
* Increases power reliability
* On-site production of power
* Reduced energy costs
* Reduction in emissions
105
What is the role of a Heat Recovery Unit in CHP?
To recover heat for use in heating or hot water.
106
What is Anaerobic Digestion?
A process to convert biodegradable materials into useful energy.
107
What does Solar Thermal Technology use to generate electricity?
Heat from the sun to create steam.
108
What is the capacity of the Bangui Wind Farm?
25 MW.
109
What is the environmental impact of renewable energy systems?
Manufacturing solar panels and wind turbines can cause pollution.
110
What is a disadvantage of renewable energy sources?
Sources are inconsistent.
111
What is the capacity of San Roque Hydroelectric Power Plant?
435 MW.
112
What is the primary function of rotating blades in a hydroelectric power plant?
To spin a generator that converts mechanical energy into electrical energy
113
What is the capacity of the San Roque Hydroelectric Power Plant?
435 MW
114
Which company owns the Magat Hydroelectric Power Plant?
SN Aboitiz Power (SNAP)
115
What is the capacity of the Kalayaan I Pumped Storage Power Plant?
168 MW
116
What are the three types of geothermal power plants?
* Dry steam plants
* Flash steam plants
* Binary cycle plants
117
What is biomass?
A non-fossilized, biodegradable organic material
118
What is an example of a biomass energy source in the Philippines?
Rice hull, coconut husks and shells, wood chips, and other agri-wastes
119
What is the capacity of the San Carlos Biopower?
19.9 MW
120
What does the RE Act of 2008 (RA no. 9513) promote?
The development, utilization, and commercialization of renewable energy resources
121
What tax benefit does the RE Act of 2008 provide for renewable energy machinery?
Duty-free importation of RE machinery, equipment, and materials
122
What is the corporate tax rate after the income tax holiday period under the RE Act of 2008?
10%
123
What is the Philippines' rank in geothermal energy production globally?
2nd largest producer
124
What is the feed-in tariff (FIT) system?
A scheme involving the obligation to generate renewable energy at a guaranteed fixed price
125
What is a green building?
A building that reduces or eliminates negative impacts on the climate and natural environment
126
What are two advantages of green buildings?
* Efficiency
* Healthier indoor environment
127
What is a disadvantage of green buildings?
High initial cost
128
What does LEED stand for?
Leadership in Energy and Environmental Design
129
What is the LEED certification for the Zuellig Building?
Platinum
130
What notable feature does the SM Aura Premier have?
Own wastewater treatment plant that recycles water for non-potable use
131
What is the purpose of the BERDE program?
To assess, measure, monitor, and certify the performance of green building projects
132
What are the four types of LEED certifications?
* Certified
* Silver
* Gold
* Platinum
133
What is one criterion for the Location and Transport category in LEED BD+C?
Access to quality transit
134
What is one challenge faced by green buildings?
Limited market awareness
135
What is a significant feature of green building design in HVAC?
Solar orientation and window placement
136
What type of energy does biomass energy produce?
Heat, which can be used directly or to generate electricity
137
Fill in the blank: The Malitbog Geothermal Power Station has a capacity of _______.
232.5 MW
138
True or False: The Philippines has the largest wind power production in Southeast Asia.
False
139
What incentive does the RE Act of 2008 provide for missionary electrification?
Cash generation-based incentive per kilowatt hour
140
What is the purpose of the Green Energy Option Program?
To allow consumers to choose renewable energy sources
141
What does the term 'sustainability' refer to in the context of renewable energy?
The ability to maintain and support renewable energy resources over time
142
What kind of materials are used in green building electrical systems?
Halogen-free wires and energy management circuit breakers (EMCB)
143
What is light?
A form of radiant energy from natural and artificial sources
## Footnote
Examples include the sun, stars, candles, and electric lamps.
144
How does light travel?
In the form of an electromagnetic wave, possessing wavelength and speed
145
Define lighting.
The application of light to illuminate objects, surfaces, scenes, pictures, people
146
Why is lighting considered both a science and an art?
It employs scientific methods and techniques while also being influenced by personal taste and artistic sense
147
What is absorption in the context of light?
The process where materials absorb part or all of the incident light, converting it into heat
148
What is selective absorption?
When materials absorb certain wavelengths while transmitting others
149
What happens when light strikes a rough surface?
It is reflected in different directions
150
What is the visible portion of the electromagnetic spectrum?
That portion to which the eye responds, from 380 to 750 nm
151
What sensation does visible energy with the shortest wavelengths produce?
Violet
152
What sensation does visible energy with the longest wavelengths produce?
Red
153
What are the primary colors of light?
* Red
* Green
* Blue
154
What are the secondary colors of light?
* Magenta
* Cyan
* Yellow
155
What is the function of the cornea in the eye?
Allows light to enter through a transparent membrane
156
What is the role of the pupil?
Limits the rays of light to the central part of the lens and adjusts for near vision
157
What is adaptation in the eye?
The ability of the eye to adjust to higher or lower levels of illuminance
158
What is photopic vision?
Vision under nominal daylight conditions operated by cones
159
What is mesopic vision?
Vision at lower light conditions where rods take over
160
What is scotopic vision?
Black and white vision at even lower light levels operated by rods
161
What is incandescence?
The method of producing light by applying heat to a solid body or vapor
162
What happens to the color of light as temperature increases?
Changes from red to orange to yellow to white
163
What is electric discharge?
Light produced when electric current passes through gas, emitting characteristic radiation
164
What is electro luminescence?
Light generated when electric current passes through certain solids
165
What is photo luminescence?
Absorption of radiation at a specific wavelength and re-emission at different wavelengths
166
Define photometry.
The science of measurement of light in terms of its perceived brightness to human vision
167
What is luminous flux (Φ)?
All the radiated power emitted by a light source and perceived by the eye
168
What is the unit of luminous flux?
Lumen (lm)
169
Define luminous intensity (I).
The visible radiant intensity of a light source in a particular direction
170
What is the unit of luminous intensity?
Candela (cd)
171
What does illuminance (E) measure?
The amount of light falling on a surface
172
What is the unit of illuminance?
Lux (lx)
173
Define luminance (L).
The brightness of an illuminated surface as perceived by the human eye
174
What is the unit of luminance?
Candelas per square meter (cd/m²)
175
What does luminous efficacy (η) indicate?
The efficiency of converting electrical power into light
176
What is the unit of luminous efficacy?
Lumens per watt (lm/W)
177
What is luminaire efficiency?
The ratio between the luminous flux emitted by the luminaire and the luminous flux of the lamp
178
What is luminous exitance (M)?
Luminous flux emitted per unit area in all directions
179
What is mean spherical candle power (MSCP)?
The average candle power of a point source in all directions
180
What is the inverse square law in illumination?
The illumination of a surface is inversely proportional to the square of the distance from the source
181
What is the cosine law in illumination?
The illuminance falls by the factor of the cosine of the angle when the surface is tilted
182
What is the coefficient of utilization?
The ratio of lumens received by a surface to total lumens emitted by a light source
183
What defines a lighting system?
One or more luminaires with one or more lamps having a characteristic lighting distribution
184
What are some early sources of artificial light?
* Glowing flames
* Oil lamps
* Candles
* Gas lighting
* Electric lamps
185
What are incandescent lamps?
Lamps that produce light by passing electric current through a filament
186
What are electric discharge lamps?
Lamps that produce light by passing electric current through a vapor or gas
187
What is color rendering index (CRI)?
A measure of the degree of color shift when illuminated by a light source
188
Define color temperature.
The absolute temperature of a blackbody radiator whose chromaticity resembles that of the light source
189
What is a luminaire?
An electrical device used to create artificial light by use of an electric lamp
190
What is the main function of luminaires?
To efficiently direct light to appropriate locations without causing glare or discomfort
191
What are direct lighting luminaires?
Luminaires that direct 90-100% of light output downward
192
What are indirect lighting luminaires?
Luminaires that direct light output upward to the ceiling and upper side walls
193
What is the primary characteristic of indirect lighting?
100% of light output is directed upward to the ceiling and upper side walls
## Footnote
Shadows are virtually eliminated in indirect lighting schemes.
194
What percentage of light is directed downward in semi-direct lighting?
60-90%
## Footnote
The remaining light is projected upwards to illuminate the ceiling and upper walls.
195
How does semi-direct lighting affect shadows?
It can soften shadows and improve room brightness.
196
What is the typical use case for semi-direct lighting systems?
Rooms with high ceilings where high levels of uniformly-distributed illumination are desired.
197
What is the light distribution in general diffuse lighting?
Downward and upward light distribution is about equal (40-60%).
198
What is the benefit of general diffuse lighting in a room?
Brightness relationships throughout the room are generally good.
199
What is Class 0 luminaire protection against electric shock?
Basic type insulation without a protective conductor for accessible conductive parts.
200
What does Class 1 luminaire protection entail?
Electrically insulated with an earthing point for exposed metal parts.
201
What is the main feature of Class 2 luminaires?
Reinforced or double insulation without provision for earthing.
202
What defines Class 3 luminaires?
Reliance on supply at Safety Extra-Low Voltage (SELV), typically 12V or 24V.
203
What does the Ingress Protection (IP) code indicate?
Degree of protection against access to hazardous parts, ingress of solid foreign objects, and water.
204
What does the 'X' in the IP code represent?
Protection of persons against contact with live parts.
205
What does the 'Y' in the IP code represent?
Protection against harmful ingress of water.
206
What is a well-designed lighting scheme supposed to provide?
Adequate illumination, avoids glare, and uniform distribution of light.
207
What is the depreciation factor in lighting design?
It accounts for the deterioration of effective candlepower due to blackening and dust accumulation.
208
What is the formula for total lumens needed for a work plane?
Total useful flux = Area x Illumination required
## Footnote
Gross lumens can be expressed as: ϕ = E x A x η x ρ.
209
What is the space/height ratio (SHR) formula?
SHR = S / H
210
Fill in the blank: A well-designed lighting scheme avoids _______.
glare and hard shadows.
211
True or False: Class 3 luminaires can be fitted with a facility for protective earthing.
False.
