Exam 1 (Mod. 1 - 6)

Two 25 ohm resistors connected in series will require a _____ voltage source to produce a 6 volt voltage drop across one 25 ohm resistor.

12

Electricity in the U.S in typically delivered in how many Volts?

120

If you have a transformer for a building that has a primary coil with 1000 turns at 12,000 volts and its secondary coil has 10 turns, This means the voltage in the secondary coil is _____ volts. This makes the transformer a step-_______ transformer.

120, down

A parallel circuit consists of three resistors. All three resistors are 20 ohms.If the current running through the third resistor is 7 amps, what is the source voltage?

140

"A circuit containing three resistors in parallel has branch currents of 3 A, 5 A, and 10 A. What is the mainline current in the circuit?"

18 A

Based on the reading, an AC circuit draws 20 amps from a 240-volt source. The watt meter measures 3,360 watts. What is the power factor? _______ % Note: Please provide the percentage value, not the decimal value.

3,360 watts/(20 amps x 240 V) = 70%

"If a single-phase electrical resistance load operates at 115 volts, how much current is required to consume 800 watts of power? (answer in amperes)"

7 AMPS

The relationship between illuminance and luminance for an opaque surface is best described as: a. Luminance and illuminance are numerically identical. b. Luminance and illuminance have the same magnitude, but opposite signs. c. Luminance is illuminance as modified by reflectance. d. Luminance and illuminance are not at all related in this situation.

Luminance is illuminance as modified by reflectance.

Match the lighting terminology below (column 1) with the parameter (column 2) it describes: - luminous flux - illuminance - luminance - luminous intensity A. quantity of light leaving a source B. density of light leaving a surface C. output of a light source in some direction D. density of light falling on a surface

Luminous flux: quantity of light leaving a source Illuminance: density of light falling on a surface Luminance: density of light leaving a surface Luminous intensity: output of a light source in some direction

Explain the difference between a Lux and a Lumen.

Lux measures the total amount of light fall on an object or surface while lumens is the amount of light coming from a source in all directions.

What organization develops and enforces mandatory grid reliability standards? A. ERCOT B. Federal Energy Regulatory Commission (FERC) C. None of the listed options D. North American Electric Reliability Corporation

North American Electric Reliability Corporation

If you have a transformer for a building that has a primary coil with 1000 turns at 12,000 volts and its secondary coil has 10 turns, This means the voltage in the secondary coil is [A] volts. This makes the transformer a step-[B] transformer.

[A] 120,[B] down

In an LED lamp, what is emitting light? a. electrons collided with mercury vapor atoms b. A coating on the inside of the glass that absorbs ultraviolet light and re-emits it as visible light. c. a diode d. a tungsten filament

a diode

"For a residential building, there:" a. are very few guidelines regarding branch circuit capacities and locations b. are numerous guidelines regarding branch circuit capacities and locations c. is a surprisingly loose attitude toward the design of circuits d. is absolutely no deviation from the prescriptive layouts shown in the NEC

are numerous guidelines regarding branch circuit capacities and locations

Room illuminance values are typically measured: a. at eye level b. on the floor c. on the ceiling d. at the work plane

at the work plane

The National Electrical Code: a. is generally indifferent about electrical wiring b. "covers power usage equipment, but not distribution components" c. is very specific about acceptable wiring materials and capacities d. has been superseded by the requirements of ASHRAE Standard 90.1

is very specific about acceptable wiring materials and capacities

As a wire's AWG number increases (say from 8 to 14) the diameter of the wire __________ . What does AWG stand for _____________?

decreases, American Wire Gauge

A luminaire that directs 0%-10% of its light output toward the ceiling is best classified as: a. semi-indirect b. diffuse c. direct d. indirect

diffuse

Glare caused by light sources in the field of vision is known as: a. a veiling reflection b. photopic overload c. reflected glare d. direct glare

direct glare

Illuminance levels and illuminance categories are used to: a. establish qualitative lighting system design criteria b. evaluate lighting system glare potentials c. select appropriate illuminant colors d. establish quantitative lighting system design criteria

establish quantitative lighting system design criteria

Illuminance levels and illuminance categories are used to: a. establish quantitative lighting system design criteria b. establish qualitative lighting system design criteria c. select appropriate illuminant colors d. evaluate lighting system glare potentials

establish quantitative lighting system design criteria

T/F: In DC Voltage, the magnitude of and direction of the current changes over time.

false

T/F: Ohms Law is the most fundamental equation in the field of electrical circuitry and is written as I=P/E.

false

T/F: The color temperature of fluorescent lamps is fixed at 3500°K.

false

The following illumination method would result in relatively uniform lighting distribution on a horizontal working plane:

general lighting

Fuses and circuit breakers: a. have similar uses but different construction and operation b. have very different uses and constructions c. are two terms for the exact same device

have similar uses but different construction and operation

Electrical power transmission networks are protected and controlled by a. high-voltage breakers. b. vacuum circuit breakers c. low-voltage breakers. d. medium-voltage breakers.

high-voltage breakers.

The inverse square law states that, for a point source :a. illuminance = (source intensity)(distance)^2 b. illuminance = (distance)^2 / (source intensity)^2 c. illuminance = (distance) / (source intensity)^2 d. illuminance = (source intensity) / (distance)^2

illuminance = (source intensity) / (distance)^2

The illumination methods (general, local, and supplemental) describe: a. types of luminaires b. intended patterns of illuminance in a space c. possible luminaire-room relationships d. predicted patterns of luminance in a space

intended patterns of illuminance in a space

Which light source has a higher color temperature, one that is describe as warm or one that is described as cool?

A cool light source has a higher color temperature than a warm light source.

Which of the following is an effect of replacing the existing grid infrastructure with a "smarter" one? A. It can be expensive B. It can become more susceptible to cybersecurity threats C. It can allow for new types of communication D. All of the above

All of the above

Which of the following is (are) not appropriate for describing a low pressure sodium lamp? a. Poor Color Rendition b. High Luminous Efficacy c. Great for use in high quality Interior Lighting.

Great for use in high quality Interior Lighting.

Which of the following is a definition of coefficient of utilization (CU)? a. Lumens on the task plane divided by total wattage of the system. b. Lumens on the task plane divided by total lumens of the lamps. c. Foot-candle level on the task plane divided by total wattage of the system. d. Total wattage of the lamps divided by total wattage of the system.

Lumens on the task plane divided by total lumens of the lamps.

Which of the following is not a main interconnection for the U.S power system? A. Western Interconnection B. Eastern Interconnection C. Southern Interconnection D. Electric Reliability Council of Texas

Southern Interconnection

The purpose of an electrical transformer is to: a. convert high-frequency utility power to 60 Hz building power b. remove noise and disturbances from utility-provided power c. convert utility-provided DC power to AC power for building use d. Step up or step down voltage for electric distribution

Step up or step down voltage for electric distribution

What part of the utility system supplies distribution substations from bulk power sources?

Subtransmission

What is the primary benefit of LED lighting?

There is no need for a bulb because the gas is replaced with a crystal of semiconducting gallium.

Please select the locations where a Medium-voltage circuit breaker can be installed. a. Substation b. Indoors c. Outdoors d. all of the above

all of the above

A _____ ______ is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current.

circuit breaker

Current is the electrical term used to describe: a. the potential for electron flow established across a circuit b. the conductor through which electrons flow c. the frequency of oscillation of ac power d. the magnitude of the flow of electrons through a circuit

the magnitude of the flow of electrons through a circuit

Energy is the technical term for this common expression: a. work b. distance c. force d. power

work

From an electrical (as opposed to architectural) point of view:a. it is always preferable to install a transformer outdoorsb. it is always preferable to install a transformer indoorsc. "if properly selected, indoor versus outdoor installation makes no difference"

"if properly selected, indoor versus outdoor installation makes no difference"

Which of the following statements are correct with respect to electrical charges? (More than one answer may be correct) Select all that apply. - Electric charges of the same polarity attract one another - Electric charges of differing polarity attract one another - Electric charges of differing polarity repel one another - Electric charges of the same polarity repel one another - none of the above

- Electric charges of differing polarity attract one another - Electric charges of the same polarity repel one another

Which of the following are the two most significant components of Light Loss Factor (LLF)? (Select all that apply.) - Temperature factor. - Lamp burnout factor. - Luminaire dirt depreciation factor. - Lamp lumen depreciation factor.

- Lamp burnout factor. - Luminaire dirt depreciation factor. - Lamp lumen depreciation factor.

In order to use a manufacturer's CU table, the designer must determine or assume which of the following parameters? (Select all that apply.) - Wall color. - Room cavity ratio. - Wall reflectance. - Reflectance of ceiling cavity and floor cavity.

- Room cavity ratio. - Wall reflectance. - Reflectance of ceiling cavity and floor cavity.

What is the advantage of a 3-phase system over a single-phase system?

- less material used - domestic and commercial power can be provided - voltage regulation is better

Semi-Direct lighting provides its own ceiling brightness. What types of fixtures support this? (Select all that apply) - pendant units - surface fixtures - Surface Mounted Fixtures - surface units - Surface-mounted fixtures - pendant fixtures

- pendant units - surface fixtures - Surface Mounted Fixtures - surface units - Surface-mounted fixtures - pendant fixtures

Please choose the best answer(s) to the following statement: What are atoms are composed of? Select all that apply. - molecules - protons - electrons - neutrons - ions

- protons - electrons - neutrons

Which of the following statements best reflects the use of direct current in buildings? a. DC is the system most commonly used. b. DC is found mainly in conjunction with battery and PV systems. c. DC is used primarily for office equipment. d. DC is prohibited by the National Electrical Code.

DC is found mainly in conjunction with battery and PV systems.

"Although electrical equipment does not require as much space as most mechanical equipment, the design of electrical systems and the layout of electrical components demand even closer interfacing with the architectural elements in space. Why?"

Depending on the electrical equipment required, sometimes they have to be located in specific areas of a building, whether it's inside the building or outside. Also, electrical rooms in buildings are almost always stacked from floor to floor so that way the flow of electricity goes down through one system.

_______________ lines serve the bulk power system and _________________ lines serve retail customers. A. Transmission; Subtransmission B. Transmission; Distribution C. Distribution; Transmission D. Radial; Distribution

Transmission; Distribution

T/F: Transformers convert electricity from low to high voltage for long-distance transmission, then convert it back to low voltage for use in homes and other facilities.

True

What type of distribution is mostly underground? A. Urban B. City C. Rural D. None of the above

Urban

"Veiling reflections" are primarily a problem that occurs with:

VDTs and specular materials

Explain the differences in wavelength and frequency.

Wavelength is the distance between waves, while frequency is the number of times a wave occurs. Wavelength is dependent on the frequency; the higher the frequency the shorter the wavelength and vice versa.

Room illuminance values are typically measured: a. at eye level b. on the ceiling c. on the floor d. at the work plane

d. at the work plane

Light is best described as: a. a small portion of a continuous range (or spectrum) of electromagnetic radiation b. a unique and specialized form of solar energy c. a form of energy not yet understood by science d. being identical to solar radiation

a small portion of a continuous range (or spectrum) of electromagnetic radiation

From the list below, select all lighting types that are classified as architectural lighting. - Emergency lighting - Ambient lighting - Decorative lighting - Stand-by lighting - Task or local lighting - Accent lighting - Safety lighting

ambient, decorative, task or local, and accent

Luminaire is the technical name for: a. an assembly of lighting fixture, lamp, ballast, and control b. reflectance from an illuminated surface c. a lighting fixture with supply or return air capabilities

an assembly of lighting fixture, lamp, ballast, and control

The purpose of a service switch is to: a. control the operation of lights and similar loads b. isolate items of electrical equipment for maintenance and repair c. automatically bring backup power systems on line d. isolate the building electrical system from the utility power system

isolate items of electrical equipment for maintenance and repair

An illuminance meter will provide readouts in which of the following units:a. candel a per square meter (or footlamberts) b. lumens (or candles) c. watts (or Btu per hour) d. lux (or footcandles)

lux (or footcandles)

Romex is a type of: a. anti-corrosion coating used on exterior wiring systems b. large-capacity busbar (typically used in industry) c. light-weight steel conduit (used in commercial/institutional buildings) d. nonmetallic sheathed cable (typically used in small buildings)

nonmetallic sheathed cable (typically used in small buildings)

The objective of an electric demand control system is: a. to reduce overall building energy use b. to reduce the size of building wiring c. to provide power at workstations whenever needed by occupants d. to reduce peak building energy consumption

of an electric demand control system is:a. to reduce overall building energy useb. to reduce the size of building wiringc. to provide power at workstations whenever needed by occupantsd. to reduce peak building energy consumption to reduce peak building energy consumption

The color rendering index (CRI) of a fluorescent lamp depends upon the: a. phosphor coating applied to the interior of the lamp b. amount of electric current passing through the lamp c. color of the lamp's glass tube d. metallic composition of the lamp filament

phosphor coating applied to the interior of the lamp

The types of light delivery systems (direct, indirect, etc) describe:

possible luminaire-room relationships

Indirect lighting can accomplish all of the following, EXCEPT: a. provide adequate illumination for all difficult seeing tasks b. eliminate shadows and glare problems c. give the impression of height in a low-ceilinged room d. provide diffuse light to the working plane

provide adequate illumination for all difficult seeing tasks

Which of the following statements is correct? Only one answer is correct. a. the resistance of copper is 1000 ohms b. the circuit symbol of a voltmeter is a square with a letter P inside of it. c. G equals 1, multiplied by R. d. resistance impedes the flow of current

resistance impedes the flow of current

The universe displays _________. a.only visible colors b. the full spectrum of light c. only red and green light d. None of the above

the full spectrum of light

T/F: AC is used in America because it can easily travel over long distances.

true

T/F: High voltage breakers are broadly classified by the medium used to extinguish the arc.

true

T/F: Transformers work through the fundamental principle of electromagnetic induction. In other words, a varying magnetic flux, associated with the loop, will induce an electromotive force across it.

true

True or false? An atom should possess an equal number of electrons and protons to make it electrically neutral.

true

Ohm's law establishes the relationship between: a. voltage, current, and resistance b. energy, power, and demand c. resistance, impedance, and reactance d. voltage, potential, and frequency

voltage, current, and resistance

Lighting power density is expressed in terms of: a. watts per luminaire b. square feet per watt c. lumens per watt d. watts per square foot

watts per square foot

Lighting power density is expressed using which of the following units: a. watts per square foot (or square meter) b. lumens per watt c. watts per lumen d. lux

watts per square foot (or square meter)