Test Study Flashcards

Question 1

Q

This is an example of what kind of signal?

Answer

A

Analog Signal

Question 2

Q

This is an example of what kind of signal?

Answer

A

Digital Signal

Question 3

Q

MP3
Audio CD
DVD
HDTV
Blu-ray video
UHD 4k video (uncompressed)
All of these require what?

Answer

A

Bit Rates

Question 4

Q

What is a digital media file Container?

Answer

A

The container (such as AVI, which stands for Audio Video Interleaved) is the structure of the file where the data is stored. The container holds the metadata (data about the data) describing how the data is arranged and which codecs are used.

Question 5

Q

What is a digital media file Codec?

Answer

A

The codec provides the method for encoding (compressing) and decoding (decompressing) the file. Many video and audio codecs are in use today, with new ones constantly being created. In some cases, the codec must be installed in the operating system to play the file.

Question 6

Q

What is the difference between Reamplification and Repeating?

Answer

A

A reamplifier reamplifies analog signals after degradation, while a repeater restates digital signals after degradation.

Question 7

Q

In a digital signal, the on state is represented by ___?
A. Two; one
B. One; two
C. Zero; one
D. One; zero

Answer

A

D. In a digital signal, the on state is represented by one, and the off state is represented by zero.

Question 8

Q

A signal that has many varying states is called a(n) ________ signal.
A. Analog
B. Fluctuating
C. Dimmer
D. Digital

Answer

A

A. A signal that has many varying states is an analog signal.

Question 9

Q

Bit depth is defined as the number of _____ you have in which to describe the value.
A. Signals
B. Speeds
C. States
D. Rates

Answer

A

C. Bit depth is defined as the number of states you have in which to describe the value.

Question 10

Q

Lossy compression is particularly suitable for the transmission of _______.
A. Spreadsheets
B. Text files
C. Financial data
D. Audio, video, and images

Answer

A

D. Lossy compression is particularly suitable for the transmission of audio, video, and images.

Question 11

Q

What is a codec?
A. A structure of data containment
B. A formatting system
C. A program that holds data
D. A device or processing system that encodes and decodes data

Answer

A

D. A codec is a device or processing system that encodes and decodes data.

Question 12

Q

As noise is introduced along a(n) ____
signal path, processing circuitry can
determine whether the signal is intended to be high or low and then retransmit a solid signal without the imposed noise.
A. Digital
B. Dirty
C. Analog
D. Clean

Answer

A

A. As noise is introduced along a digital signal path, processing circuitry can determine whether the signal is intended to be high or low and then retransmit a solid signal without the imposed noise.

Question 13

Q

Noise overcomes the signal after many generations of re-amplification of a(n)
_____ signal.
A. Digital
B. Analog
C. Low
D. High

Answer

A

B. Noise overcomes the signal after many generations of re-amplification of an analog signal.

Question 14

Q

What is this graph measuring?

Answer

A

Wavelength

Question 15

Q

If a wavelength is 20Hrz, is it high or low frequency?

Answer

A

It is high frequency. The higher the number the higher the frequency.

Question 16

Q

What is the formula for the decibel measurement of power?

Answer

A

dB = 10 x log10 (P1/P2)

Question 17

Q

What is the decibel measurement for voltage?

Answer

A

dB = 20 × log(V1/V2)

Question 18

Q

What is the decibel measurement for distance?

Answer

A

dB = 20 × log(D1/D2)

Question 19

Q

What is Omnidirectional sound?

Answer

A

Sound pickup is uniform in all directions.

Question 20

Q

What is Cardioid (unidirectional) sound?

Answer

A

Pickup is primarily from the front of the microphone (one direction) in a cardioid pattern. It rejects sounds coming from the side, but the most rejection is at the rear of the microphone. The term cardioid refers to the heart-shaped polar patterns.

Question 21

Q

What is Hypercardioid sound?

Answer

A

A variant of the cardioid, this type is more directional than the regular cardioid because it rejects more sound from the side. The trade-off is that some sound will be picked up directly at the rear of the microphone.

Question 22

Q

What is Supercardioid sound?

Answer

A

This type provides better directionality than the hypercardioid, as its rejection from the side is better. It also has more rear pickup than the hypercardioid.

Question 23

Q

What is Bidirectional sound?

Answer

A

Pickup is equal in opposite directions, with little or no pickup from the sides. This is sometimes also referred to as a figure-eight pattern because of the shape of its polar patterns.

Question 24

Q

Describe the characteristics of Compressors.

Answer

A

They reduce the level of all signals above an adjustable threshold. In other words, they keep loud signals from being too loud.
• The amount of reduction above the threshold is derermined by an adjustable ratio
• The reduction reduces the variation between highest and lowest signal levels, resulting in a compressed (smaller) dynamic range.
• They can be used to prevent signal distortion.

Question 25

Q

Describe the characteristics of Limiters.

Answer

A

• They limit the level of all signals above an adjustable threshold. In other words, they prevent high-amplitude signals from getting through.
• Limiting is used to prevent damage to components such as loudspeakers.
• They are triggered by peaks or spikes in the audio signal (like a dropped microphone), and they react quickly to cut them off before they exceed a certain point.
• The amount of limiting above the threshold is determined by a more aggressive ratio than a compressor reduction ratio.
• The reduction limits the variation between highest and lowest signal levels, resulting in a limited dynamic range.

Question 26

Q

Describe the characteristics of Expanders.

Answer

A

• They reduce the level of all signals below an adjustable threshold.
• The amount of reduction below the threshold is determined by an adjustable ratio.
• The signal-level reduction increases the variation between highest and lowest signal levels, resulting in an increased dynamic range.
• They are used for reducing unwanted background noise.

Question 27

Q

Describe the characteristics of Gates.

Answer

A

• They can be thought of as an extreme downward expander.
• They mute the level of all signals below an adjustable threshold.
• Signal levels must exceed the threshold setting before they are allowed to pass.
• They can be used to automatically turn off unused microphones.

Question 28

Q

Describe the characteristics of Filters.

Answer

A

• They filter (attenuate) certain frequencies from a signal.
• A notch filter “notches out” (attenuates) a specific narrow-frequency range.
• Low-pass filters pass the low-frequency content of a signal and attenuate the high-frequency range.
• High-pass filters pass the high-frequency content of the signal and attenuate the low-frequency range.

Question 29

Q

What is a Graphic equalizer?

Answer

A

A common graphic equalizer is the 1/3-octave equalizer, which provides 30 or 31 slider adjustments corresponding to specific fixed frequencies with fixed bandwidths. The frequencies are centered at every one-third of an octave. The numerous adjustment points allow for shaping the overall frequency response of the system to produce the required effect. The graphic equalizer is so named because the adjustment controls provide a rough visual, or graphic, representation of the frequency adjustments.

Question 30

Q

What is a Parametric equalizer?

Answer

A

A parametric equalizer offers greater flexibility than a graphic equalizer. Not only does the parametric equalizer provide boost and cut capabilities, as does the graphic equalizer, but it also allows center frequency and filter bandwidth (often called the filter’s O adjustments.
A simple parametric equalizer can be found on the input of many audio mixers.

Question 31

Q

An audio digital signal processor (DSP) is a microprocessor-based device that analyzes the incoming digital audio streams and performs mathematical manipulations and transformations on the signals to produce a range of functions, may include what?

Answer

A

• Mixing
• Automated level control
• Filtering
• Equalization
• Limiting
• Compression and/or expansion
• Time delay
• Pitch shifting
• Echo cancellation
• Feedback suppression
• Temporal manipulation
• Matrix routing and mixing
• Loudspeaker processing

Question 32

Q

What are typical loudspeaker voltage levels?

Answer

A

• 4 volts or more for typical sound systems
• Up to 70 or 100 volts in a distributed sound system
• More than 100 volts in extremely large venues

Question 33

Q

What are the primary functions of loudspeakers?

Answer

A

• Communication
Simple public address, intercom, evacuation and warning
systems, and radio communications
•Sound reinforcement Lectures, presentations, musical performances, concerts, theater productions, artist foldback
• Sound reproduction
Playback of prerecorded material such as music and video
soundtracks.

Question 34

Q

What are the three most common loudspeaker impedance ratings?

Answer

A

4 Ohms
8 Ohms
16 Ohms

Question 35

Q

What can knowing a speakers impedance help with?

Answer

A

• Achieve optimum system volume
• Avoid wasting power
• Avoid overloading and damaging your power amplifier
• Prevent damage to your loudspeakers
• Reduce distortion and noise
• Avoid uneven sound distribution

Question 36

Q

What is the difference between a balanced and unbalanced circuit?

Answer

A

Balanced circuits send signal over multiple lines that combine to form a full, uninterrupted signal.
Unbalanced circuits send signal over a single line, allowing interference and spiking to pass through the circuit.

Question 37

Q

How sound moves through the air is called _____.
A. Generation
B. Compression
C. Acoustical
D. Propagation

Answer

A

D. How sound moves through the air is called propagation.

Question 38

Q

Wavelength is the _____.
A. Number of times a wavelength cycle occurs per second
B. Intensity or loudness of a sound in a particular medium
C. Physical distance between two points of a waveform that are exactly one cycle apart
D. Cycle when molecules move from rest through compression to rest to rarefaction

Answer

A

C. Wavelength is the physical distance between two points of a waveform that are exactly one cycle apart.

Question 39

Q

Which of the following does OdB SPL describe?
A. The threshold of human hearing
B. Ambient noise level
C. The threshold of pain
D. Normal listening level

Answer

A

A. OdB SPL describes the threshold of human hearing.

Question 40

Q

A “just noticeable” change in sound pressure level, either louder or softer, requires a ______ change.
A. +/-10dB
B. +/-6dB
C. +/-1dB
D. +/-3dB

Answer

A

D. A “just noticeable” change in sound pressure level, either louder or softer, requires a +/-3dB change.

Question 41

Q

Acoustics covers how sound is _______, and its _______ and _____.
A. Received; effects; structure
B. Produced; propagation; control
C. Controlled; delivery; translation
D. Produced; amplification; reception

Answer

A

B. Acoustics covers how sound is produced and its propagation and control.

Question 42

Q

Numerous, persistent reflections of sound are called ______.
A. Directional sound
B. Echo
C. Surface reflection
D. Reverberation

Answer

A

D. Numerous, persistent reflections of sound are called reverberation.

Question 43

Q

Ambient noise is sound that ______ the desired message or signal.
A. Interferes with
B. Completely blocks
C. Enhances
D. Is louder than

Answer

A

A. Ambient noise is sound that interferes with the desired message or signal.

Question 44

Q

The audio signal ends up in a(n)
______ before being converted into acoustical energy.
A. Output device
B. Electrical signal
C. Processor
D. Microphone

Answer

A

A. The audio signal ends up in an output device before being converted into acoustical energy.

Question 45

Q

The strength of the electrical audio signal from a microphone is called a(n) _____-level signal.
A. Dynamic
B. Condenser
C. Electret
D. Mic

Answer

A

D. The strength of the electrical audio signal from a microphone is called a mic-level signal.

Question 46

Q

Phantom power is the ________ required to power a condenser microphone.
A. Polarized conductor
B. Electrical field
C. Remote power
D. Internal capacitor

Answer

A

C. Phanton power is the remote power required to power a condenser microphone.

Question 47

Q

Typically, what type of connector finishes the shielded twisted-pair cable?
A. XRL,
B. RXL
C. IRX
D. XLR

Answer

A

D. An XLR connector typically finishes the shielded twisted-pair cable.

Question 48

Q

The simultaneous use of multiple wireless microphone systems requires ______.
A. Frequency coordination
B. Multiple receivers all tuned to the same frequency
C. Using lavalier microphones
D. Using IR wireless microphones

Answer

A

A. The simultaneous use of multiple wireless microphone systems requires frequency coordination.

Question 49

Q

If a technician changes the level of a signal, it is called _____.
A. Unity gain
B. Gain adjustment
C. Attenuation
D. Signal expansion

Answer

A

B. If a technician changes the level of a signal, it is called gain adjustment.

Question 50

Q

The amplifier comes right before _____ in the audio system chain.
A. The equalizer
B. Everything
C. The audio processor
D. The loudspeakers

Answer

A

D. The amplifier comes right before the loudspeakers in the audio system chain.

Question 51

Q

What is a crossover?
A. A loudspeaker containing multiple drivers
B. A loudspeaker enclosure with more than one frequency range
C. An electrical frequency dividing network circuit
D. A single driver reproducing the entire frequency range

Answer

A

C. A crossover is an electrical frequency-dividing network circuit.

Question 52

Q

What kind of circuit does this represent?

Answer

A

DC (direct current) Circuit

Question 53

Q

What kind of circuit does this represent?

Answer

A

AC (alternate current) Circuit

Question 54

Q

What kind of circuit does this represent?

Answer

A

Series Circuit

Question 55

Q

What kind of circuit does this represent?

Answer

A

Parallel Circuit

Question 56

Q

What does this graph illustrate?

Answer

A

Visible light spectrum within the electromagnetic spectrum.

Question 57

Q

What is Candela per square meter or Nit?

Answer

A

Sometimes referred to as the Nit (nt), the
candela per square meter is the international unit of luminance. A nit is equal to a luminance of 1 candela per square meter.

Question 58

Q

What is the definition of Candela?

Answer

A

The candela is the base unit of luminous intensity. It is the amount of light emitted by a light source that just happens (after a bit of manipulation of the specification) to have a similar output to a historic standard wax candle. That’s why it’s called candela, which is the Latin word for candle.

Question 59

Q

What is the definition of Lumen?

Answer

A

The lumen is the unit of luminous flux the quantity of photons emitted from a 1 candela light source through an area of 1 square meter on a sphere 1 meter in radius surrounding that light source. Lumens are the most common unit of measurement of light output from a projector or a light source.

However, different organizations measure lumens by different methods. The most commonly quoted standard for the lumen measurement worldwide is the method specified by the American National Standards Institute (ANSI, despite no longer being the international standard method.

Question 60

Q

What is the difference between an incident meter and a reflected meter?

Answer

A

Incident meters measure the light coming directly from a source such as a lamp, projector, lighting fixture, digital sign, video wall, or monitor.

Reflected meters, or spot meters, measure the light that bounces off an object like a projection screen, a wall, a participant in a video conference, or a work surface.

Question 61

Q

What is the definition of Lux?

Answer

A

Lux is the standard international unit of illuminance, the measure of the luminous flux (lumens) falling on a specified area. One lux is equal to 1 lumen/ square meter. Generally, illuminance is measured at a task area such as a video screen. a note-taking location or a work area.

Question 62

Q

What is the definition of Foot-candle?

Answer

A

The foot-candle (fc) is the U.S. customary measurement of illuminance. One foot-candle is equal to 1 lumen/square foot. One foot-candle equals approximately 10.76 lux. One lux equals approximately 0.093fc.

Question 63

Q

What is the definition of Foot-lambert?

Answer

A

The foor-lambert (A) is the U.S. customary unit of measurement for luminance. It is equal to 1/n candela per square foot. A foot-lambert is approximately 3.43 candela per square meter.

Question 64

Q

What are the three dimensions of color?

Answer

A

• Hue The underlying spectrum color- red, orange, yellow, green, blue, indigo, or violet)
• Value/brightness The grayscale value of the color-its position on the scale between white and black
• Saturation/Chroma The saturation or amount of the hue its position on the scale between a pale, pastel tint and a strong, bold color

Answer 65

A

Serial Digital Interface (SDI)

Answer 66

A

[(TP x FR)/2] × 3
(TP = total number of pixels)
(FR = frame rate)

Answer 67

A

Front-screen projection uses the reflective method. The light from a projector reflects off a screen and hits our eyes. Reflective applications allow for the possibility of large displays and are easy to install. However, front projection has a lower contrast ratio than other methods, and because the projector is located in the room, it creates potential for fan and projector noise in the audience area.

Answer 68

A

LED, organic light-emitting display (OLED), and microLED displays use the emissive method. The light is created by the individual elements of the display and sent directly outward.

Answer 69

A

Refraction is the bending or changing of the direction of a light ray when passing through the boundary between different materials, such as between glass and air. How much light refracts, meaning how great the angle of refraction, is called the refractive index. The refractive indexes of the materials used in a lens have an impact on the image quality from that lens.

Answer 70

A

Dispersion can be seen when a white light beam passes through a triangular prism. The different wavelengths of light refract at different angles, dispersing the light into its individual components. Lenses with strong dispersion can produce images with color fringes, known as chromatic aberration.

Answer 71

A

Light passing through the edge of a spherical lens leaves the lens at a different angle to the light passing through the center of the lens and so has a different focal length. The resulting distortion is called spherical aberration.

Answer 72

A

Curvature of field results in blurry appearance around the edge of an otherwise in-focus object (or the reverse). This is the result of a curved lens that projects a curved image field onto a flat surface such as projection screen. The more steeply curved the projection lens and the closer it is to the screen, the more noticeable is the effect. Very short focal length (wide angle) spherical lenses have steep curves.

Answer 73

A

4:3
16:9
16:10

1.3333:1
1.7777:1
1.60:1

Answer 74

A

Similarly to a 3LCD system, light from the projector’s light source is split into the three video primary colors- red, green, and blue. Each color of light is directed at a separate DMD chip, which creates the pixel pattern for that color component of the image. The images from the three DMD chips are optically combined to form an additive full-color image.

Answer 75

A

In these systems, a single DMD device produces the entire image. It is alternately illuminated at high speed by the component colors usually, but not always, red, green, and blue to form an additively mixed full color image due to the viewers’ persistence of vision. The alternating colors illuminating the DMD are usually generated by passing the white light from the projector’s light source through a rapidly spinning filter wheel that has segments of each of the component colors. The color wheel is synchronized with the patterns being sent the DMD chip.

Answer 76

A

Screen gain is the ability of a screen to redirect light rays into a narrower viewing area, making projected images appear brighter to viewers sitting on-axis to the screen. The higher the gain number of a screen, the narrower the viewing angle over which it provides optimal brightness.

Answer 77

A

• Passive viewing is where the content does not require assimilation and retention of detail, but the general intent is to be understood (e.g., noncritical or informal viewing of video and data). This requires a minimum contrast ratio of 7:1.
• Basic decision-making (BDM) requires that a viewer can make decisions from the displayed image but that comprehending the informational content is not dependent upon being able to resolve every element detail (e.g., information displays, presentations containing detailed images, classrooms, boardrooms multipurpose rooms, product illustrations). This requires a minimum contrast ratio of 15:1. godstami
• Analytical decision-making (ADM) is where the viewer is fully analytically engaged with making decisions based on the details of the content right down to pixel level (e.g., medical imaging, architectural/engineering drawings, fine arts, forensic evidence, photographic image inspection). This requires a minimum contrast ratio of 50:1.
• Full-motion video is where the viewer is able to discern key elements present in the full-motion video, including detail provided by the cinematographer or videographer necessary to support the story line and intent (e.g., home theater, business screening room, broadcast post-production). This requires a minimum contrast ratio of 80:1.

Answer 78

A

%EH = Element height / total image height

Answer 79

A

L = SH x SW × AI

L = Lumens
SH = Screen height
SW = Screen width
Al = Average illuminance

Answer 80

A

D. Electromagnetic radiation is categorized by its wavelength.

Answer 81

A

D. Generally, a lux measurement of incident light is taken at a task area like a video screen.

Answer 82

A

B. Illumination decreases by 75 percent when the distance from a light source is doubled.

Answer 83

A

A. The amount of ambient light in a displayed environment negatively affects the quality of the displayed image.

Answer 84

A

B. The native resolution of display device is defined by its horizontal rows and vertical columns of pixels.

Answer 85

A

D. According to the Projected Image System Contrast Ratio standard, the minimum contrast ratio required for viewing full-motion video is 80:1.

Answer 86

A

D. The four factors related to primary optics that influence the quality of the projected image are refraction, dispersion, spherical aberration, and curvature of field.

Answer 87

A

C. Three of the major formats of digital video connections are DVI, HDMI, and DisplayPort.

Answer 88

A

A. To measure the bandwidth of an image, you will need a spectrum analyzer.

Answer 89

A

C. Rear-screen display applications are considered transmissive.

Answer 90

A

B. LCDs first pass light through a polarizer, which blocks certain light waves.

Answer 91

A

D. When selecting a display type, your first step should be to determine what you want to display.

Answer 92

A

A. The higher the gain number of a projection screen, the brighter the image.

Answer 93

A

D. If the phase setting of a display needs adjusting, the details of the image will be fuzzy.

Answer 94

A

Local area network (LAN):
A LAN connects devices within a confined geographical area, such as a building or living complex. A LAN is typically used to connect network devices over a short distance and generally owned or controlled by the end user.

Wireless local area network (WLAN): A WLAN is a wireless LAN.

Campus area network (CAN): A CAN connects multiple LANs in a limited geographical area such as a university campus or a cluster of buildings.

Metropolitan area network (MAN): A MAN is a communications network that covers a geographic area, such as a suburb or city.

Wide area network (WAN): A WAN covers a wide geographic area, such as a state or country. The Internet is the largest WAN it covers the earth. LANs are connected to WANs through routers, which are discussed later in this chapter.

Storage area network (SAN): A SAN is a high-speed, special-purpose network
(or subnetwork) that interconnects data-storage devices.

Virtual local area network (VLAN): A VIAN is created when network devices on separate LAN segments are joined to form a logical group, thereby spanning the logical LANs to which they are connected.

Personal area network (PAN): A PAN is a limited-range wireless network that
serves a single person or small workgroup.

Answer 95

A

• Single-mode: Single-mode means that the transmitted light travels on a single light path. You can typically identify single-mode fiber-optic cable by its yellow 0 outer protective jacket.
• Multimode: Multimode means it travels on multiple light paths. Multimode fiber-optic cable is identified by an orange jacket.

Answer 96

A

• Application: The Application layer includes the functions of the Application, Presentation, and Session layers (layers 5 through 7) of the OSI model.
• Transport: The Transport layer matches the Transport layer of the OSI model.
• Internet: The Internet layer matches the function of the Network layer of the
OSI model.
• Network Access: The Network Access layer includes the functions of the Data
Link and Physical layers (layers 1 and 2) of the OSI model.

Answer 97

A

Layer 1, the Physical layer, covers cabling and other connection mediums, such as patchbays and more. The Physical layer does the following:
Defines the relationship between the device and a physical means of sending data over network devices (such as a cable)
• Defines optical, electrical, and mechanical characteristics

Layer 2, the Data Link layer, includes the Ethernet standard and unique hardware addresses. Switches and Bridges operate ar this layer. The Data Link layed lues he following.
. Defines procedures for operating the communication links
. Encapsulates data into Ethernet frames
. Detects and corrects packet-transmission errors

Layer 3, the Network layer, is where the Internet Protocol (IP) comes into play. Routers and layer 3 switches operate at this level. The Network layer does the following.
. Determines how data is transferred between network devices . Routes packets according to unique network device addresses
. May provide flow and congestion control to prevent network resource depletion

Layer 4, the Transport layer, governs the transfer of data. Gateways operate at this level. The Transport layer does the following:
• Provides reliable and sequential packet delivery through error-recovery and flow-control mechanisms
• Provides connection-oriented or connectionless packet delivery
• Provides flow and congestion control to prevent network resource depletion

Layer 5, the Session layer, is the first of the upper layers and concerns the data itself, ensuring data passes properly through the network. The Session layer does the following:
• Manages user sessions and dialogues
• Controls the establishment and termination of connections between users
• Reports upper-layer errors

Layer 6, the Presentation layer, unpackages data for use by the Application layer,
It also does the following.
• Masks data format differences between dissimilar systems so they can communicate
• Specifies an architecture-independent data-transfer format
• Encodes and decodes data, encrypts and decrypts data, and compresses and decompresses data

Layer 7, the Application layer, presents data to the application software for use.
The Application layer also does the following:
• Defines an interface to user processes for communication and data transfer in a network
• Provides standardized services, such as file and job transfer, and operations

Answer 98

A

The IPv4 format requires a number made up of four 8-bit “chunks,” called octets, such as the following:

192.168.1.25

This number is actually a 32-digit binary number that looks like this:

11000000.10101000.00000001.00011001

Answer 99

A

Instead of using a binary numbering system consisting of four groups of octets, IPv6 uses eight groups of four hexadecimal numbers. This change in number structure raises the number of unique network addresses.

• IPv4 has 2 to the 32 power, or 4,294,967,296, potential IP addresses.

• IPv6 has 2 to the 128 power, or 340,282,366,920,938,463, 463,374,607,431,768,211,456, potential addresses.

In practice, an IPv6 address looks something like this:

FEDC:BA98:7654:3210:FEDC:BA98:7654:3210

Answer 100

A

• Unmanaged: An unmanaged switch is one you simply plug in and connect devices- that’s it. There are no adjustments. It just works.

• Managed: Managed switches give the IT manager the ability to adjust port speeds, set up VLANs, set up quality of service (QoS) settings, monitor traffic, and more. Managed switches are what you will find in most complex or multifunction networks.

Answer 101

A

A. A bus network connects devices in sequence along a linear path.

Answer 102

A

D. The IEEE 802.11 standard defines Wi-Fi communications methods.

Answer 103

A

C. The connection speed in a Wi-Fi connection slows down if the signal strength declines.

Answer 104

A

D. Single-mode fiber-optic cable can be identified by its yellow outer jacket.

Answer 105

A

B. The OSI reference model is a guide that assists with conforming network communications and their processes to standards.

Answer 106

A

C. In the OSI model, cabling and patchbays are elements of layer 1, the Physical layer.

Answer 107

A

D. A MAC address is unique to every device and identifies a network’s equipment.

Answer 108

A

A. IP deals with addresses on a network.

Answer 109

A

B. An IPv6 address uses eight groups of four hexadecimal numbers.

Answer 110

A

C. Subnet masks can indicate how many devices are allowed on the network.

Answer 111

A

D. An IP address and subnet mask are required to set an IP address manually on a network.

Answer 112

A

D. A DHCP server automatically assigns an IP address to the MAC address during the device’s connection to a network.

Answer 113

A

A. Unmanaged switches just need to be plugged in and connected to devices.

Answer 114

A

B. A gateway sends packets to different locations on a network and connects to outside networks.

Answer 115

A

C. A firewall controls incoming and outgoing network traffic and determines what will be allowed through.

Answer 116

A

6.5mm (1/4-inch) phone

Answer 117

A

3.5mm (1/8-inch) phone

Answer 118

A

RCA (phono)

Answer 119

A

RJ-45 (8PSC or 8-pin, &-conductor)

Answer 120

A

Speakon (NL4)

Answer 121

A

Captive screw, Euroblock, Phoenix

Answer 122

A

DVI (Digital Visual Interface)

Answer 123

A

HD15 (VGA)

Answer 124

A

HDMI (High-Definition Multimedia Interface)

Answer 125

A

DisplayPort

Answer 126

A

USB (Universal Serial Bus)

Answer 127

A

SC Connector

Answer 128

A

ST Connetor

Answer 129

A

LC Connector

Answer 130

A

A. The path on which signal types travel is called signal flow.

Answer 131

A

D. The purpose of shielding is to prevent noise from mixing with the signal.

Answer 132

A

C. Cable contains multiple conductors.

Answer 133

A

D. Twisted-pair cable using balanced circuitry can help in rejecting interference.

Answer 134

A

B. Unless amplified or buffered, digital signals generally do not travel as far as analog signals.

Answer 135

A

D. Switchers allow the user to select one input from a number of inputs.

Answer 136

A

A. A 4 x 2 matrix switcher can connect any of four inputs to one or both of two outputs.

Answer 137

A

C. An AV rack is a housing unit that protects and organizes electronic equipment.

Answer 138

A

B. The inside of a typical AV rack is 19 inches (482.6mm) wide, and the outside varies from 21 to 25 inches (533 to 635mm).

Answer 139

A

• Raising or lowering a projection screen

• Commanding a switcher to change an input

• Setting volume levels

• Routing a signal from one device to another

• Powering on devices

• Opening or closing drapes

• Activating various functions on a single device (play, pause, and stop)

Answer 140

A

• Power up the haze and smoke machines

• Power up the effects lighting system

• Power up the show replay system

• Power up the projectors, video processor, and video displays

• Power up the speaker arrays

• Power up the animatronics system

• Switch the audio and video inputs to the preshow players

• Display the preshow video content

• Play the preshow music

• Wait 10 minutes

• Lower house light levels in the room

• Fade out the preshow music and video

• Switch the video and audio inputs to the show replay system

• Trigger the show replay system

• Turn on external “Show in Progress” signs

Answer 141

A

. RS-232 The Electronic Industries Association (EIA) Recommended Standard 232 (RS-232) is a point-to-point protocol that uses an unbalanced line and is thus susceptible to external noise.

• RS-422 provides a balanced, four-wire (separate transmit and receive links) serial data signaling system that enables cable runs of up to 1,200 meters (4,000 feet).

• RS-485 standard is a balanced, transmission-line serial communications protocol that supports up to 32 transmitting and receiving devices or, in some applications, 256 transmitting and receiving devices.

. USB Universal Serial Bus, among its many other applications, is a serial data signaling system that is widely used for device control in AV systems. While USB may be limited to transmission distances less than 5 meters (16 feet), there are USB-to-Ethernet adapter systems that use ICP/IP to allow USB control to be extended to any point on the Internet.

Answer 142

A

• Zigbee is a relatively inexpensive, low-energy, low-speed wireless communications protocol that was designed for remote device communication and control over a small area such as a house or an office, with a maximum range of about 30 meters (100 feet) line of sight.

• Wi-Fi is a general data communications protocol used for computer networking. Because of its wide implementation across most spaces where AV systems are used, and because of the wide availability of devices with integrated Wi-Fi capabilities, it is used for both control communications and data distribution.

• Bluetooth is a low-energy data communications protocol designed for personal area networking over distances up to about 10 meters (30 feet) line of sight.

Answer 143

A

D. Control systems simplify the operation of an AV system.

Answer 144

A

B. Flip charts are not a common method of interfacing with a control system.

Answer 145

A

D. Setting volume levels is more likely to be a function than a program.

Answer 146

A

C. Powering on the audio amplifier and display would most likely be a program.

Answer 147

A

D. The purpose of a control system interface is to send instructions to the control system CPU.

Answer 148

A

B. Communication that allows a return message is called bidirectional.

Answer 149

A

D. Contact-closure control communication provides device operation by closing or opening an electrical contact.

Answer 150

A

D. Bright sunshine or fluorescent lighting can interfere with an I control.

Answer 151

A

A. Ethernet is mainly used in control systems to control complex systems.

Answer 152

A

D. Voltage is the force that causes current to flow through a conductor.

Answer 153

A

A. Current is measured in amperes.

Answer 154

A

C. The opposition to the flow of current in an AC circuit is called impedance.

Answer 155

A

D. Power is measured in watts.

Answer 156

A

C. The relationship between voltage, current, and resistance is defined by the
formula I = V/R.

Answer 157

A

D. A current is always seeking to return to the source.

Answer 158

A

B. The main panel distributes power using feeders and distribution panels.

Answer 159

A

D. The branch circuits that power wall outlets and AV equipment are connected to the subsidiary distribution panel (panelboard).

Answer 160

A

B. When planning an electrical system, do not plan to exceed 80 percent of the current capacity of any circuit.

Answer 161

A

• Radio waves are part of the spectrum of electromagnetic radiation. They are a result of the movement of electric charge (current), which generates an electric field, a magnetic field, and electromagnetic radiation.

• Radio frequency (RF) refers to any signal with a frequency in the range from 3kHz to 300GHz. An RF signal does not have to be carried by radio waves; it can be carried in a copper cable, by a laser link, by an infrared link, or in a fiber-optic cable.

• Wireless refers to any signal that is carried without a wire or a fiber-optic cable connection. Radio waves, laser beams, and infrared signals are all examples of wireless connections. The handheld infrared remote control for a projector is an example of wireless communication that does not use radio waves.

Answer 162

A

D. An AC signal of 3kHz to 300GHz falls into the RF spectrum.

Answer 163

A

A. A transmitter modulates its incoming signal stream to be sent out via antenna.

Answer 164

A

D. Modulation is the most important step in converting data in a transmitter.

Answer 165

A

D. The range of frequencies between 300MHz and 3GH Iz is the UHF band.

Answer 166

A

A. One of the most efficient configurations for a vertical antenna is to have a Physical length one-quarter of the signal wavelength.

Answer 167

A

C. The main function of a diversity receiver is to compare the phase differences between signals to avoid cancellation.

Answer 168

A

B. Parabolic antennas are ideal for use in point-to-point communications.

Answer 169

A

• Administrative representatives/stakeholders, including owner executives, facility managers, department heads, and funding organizations

• End users, including representatives from each organization or department that will use the new systems

• AV technology managers, representing the technical side of the dients AV operational needs

• IT representatives, to address issues in utilizing or accessing the IT system and how IT relates to the users activities

• Architects and project designers, to provide input regarding space allocation and planning

• Program, production, or construction managers, who may be stakeholders in the overall project outcome

Answer 170

A

• The specific activities the end users want to accomplish within the space/room
• The required AV presentation applications based on the users’ needs
• The tasks and functions that support the applications

Answer 171

A

• Space allocation

• Security

• Electrical/lighting

• Data/telecommunications

• Structural

Answer 172

A

Benchmarking refers to the process of examining methods, techniques, and principles from peer organizations and facilities. AV designers and integrators can use these benchmarks as a basis for designing a new or renovated facility.

Answer 173

A

• Mechanical services drawings show the ductwork that goes through the building.

• Engineering drawings show the load-bearing and suspension points.

• Electrical drawings show locations of power and lighting.

• Engineering drawings show the location of communications and networking cabling, patch facilities, and distribution frames.

• Reflected ceiling plans depict the ceiling grid, diffusers, light fittings, sprinklers, projection system, and loudspeakers.

• Site drawings locate geographically where you will need to go to perform the installation.

Answer 174

A

• Limitations on times of day when on-site work is acceptable

• Limitations to on-site work activities

• Security

• Noise limitations

• Limitations on parking or loading vehicles

• Areas that require special care or attention

• Locations that present potentially dangerous conditions or require special procedures

• Ongoing construction

• Cultural issues

Answer 175

A

C. Active listening includes focusing on what the person is saying, summarizing and paraphrasing the person’s statements, and maintaining eye contact with a person. It does not include asking frequent questions to guide the conversation to the topic you are interested in discussing, because the point of active listening is to actually hear what the client is trying to communicate.

Answer 176

A

B. Usually, the best approach for communicating detailed technical AV plan information to a client is to send the client an electronic document containing the information. Other methods, such as e-mail, text, messaging, or telephone conversations, are likely too informal to enable the client to review the detailed information.

Answer 177

A

C. The most valuable source of information when defining the needs for an AV system is usually end-user descriptions of the tasks and applications the AV system will support.

Answer 178

A

D. The main purpose of an initial needs analysis is to identify the activities that the end users will perform and the functions that the AV system should provide to support these activities.

Answer 179

A

A. Knowledge of the overall room function assists the AV system designer by providing a starting point from which to determine client needs.

Answer 180

A

A. Task parameters are used to provide overall information about the desired general AV needs.

Answer 181

A

B. The purpose of benchmarking is to give the client an opportunity to experience a number of AV system designs that address similar needs.

Answer 182

A

A. It is important for the AV vendor to obtain a full set of building plans because the AV designer must understand the full range of room features to ensure that the AV system design takes other building systems and components
into account.

Answer 183

A

D. The AV team should collect the full range of client contact information, including the main client contact and the client technical representative. Also, the AV team should collect information about any contacts who may be required for site inspection and installation, including the architect, building manager, construction manager, security manager, IT manager, and so on.

Answer 184

A

C. The AV team uses information about any identified constraints to the AV design and installation tasks to develop a work-around plan when these constraints will affect the design or installation tasks.

Answer 185

A

• PPE

• Approved ladders

• Fall protection

Answer 186

A

• Architectural drawing package: The drawings in this package illustrate the overall design of the building and rooms. These include the room layouts; features and dimensions; and locations of building systems such as HVAC, plumbing, lighting, data and communications, and electricity.

• AV project drawing package: This package provides the overall picture for an AV installation. These plans, created by the AV system designer, depict the equipment, where each component will be located, and how each component should be physically installed.

Answer 187

A

Plan view

Answer 188

A

Reflected ceiling plan

Answer 189

A

Elevation drawing

Answer 190

A

Section drawing

Answer 191

A

Detail drawing

Answer 192

A

Title block

Answer 193

A

Elevation flag

Answer 194

A

Section cut flag

Answer 195

A

Detail flag

Answer 196

A

Grid system symbol

Answer 197

A

Elevation drawings only show the wall and what’s mounted to it. Section drawings show a perspective from inside the room, including other furniture.

Answer 198

A

B. When visiting a client site, the primary work site regulations governing the use of PPE are typically defined by the AHJ (Authority having jurisdiction). However, keep in mind that the client, the client’s insurance company, and your company may also have safety requirements that you should follow.

Answer 199

A

B. The safety equipment that AV technicians should use when working at a site include PPE (such as hard hats, work boots, gloves, and safety glasses), approved nonconductive ladders, and fall protection. Nonslip handle tools are not typically considered required safety equipment.

Answer 200

A

D. A site survey checklist is typically used to capture general information about a client and site that may be relevant for the A system design and installation tasks.

Answer 201

A

A. Reflected ceiling plans depict the layout of items on the ceiling.

Answer 202

A

A. Mechanical drawings depict the ductwork that goes through the building.

Answer 203

A

A. Elevation drawings depict the characteristics of a wall using a side view, which would allow you to determine the appropriate height and location of a video display.

Answer 204

A

C. Section drawings depict the structures behind a wall or above a ceiling that could interfere with your system installation plan.

Answer 205

A

B. A detail drawing would depict exactly how the designer wants the projector mounted to the ceiling.

Answer 206

A

A. The abbreviation NTS refers to “not to scale” and is used to tell you something on the drawing is not consistent with the scale.

Answer 207

A

D. The abbreviation AFF refers to “above finished floor” and would indicate how high on a wall the interface plate would be installed.

Answer 208

A

A. Mechanical drawings provide the best information about the ducts and piping in a facility.

Answer 209

A

A. On a drawing with a 1:50 scale, 2 centimeters equal 100 centimeters, or 1 meter.

Answer 210

A

A. On a drawing using a 1/4 scale, 6 inches equal 24 feet.

Answer 211

A

A. A section cut symbol on a drawing indicates a sectional view through a part of the structure.

Answer 212

A

A. The equation 25.4 × 10 = 254mm allows you to convert a measurement of
10 inches into an equivalent measurement in millimeters.

Answer 213

A

C. The equation 100 / 25.4 = 3.94in allows you to convert a measurement of
100 millimeters into an equivalent measurement in inches.

Answer 214

A

C. The area of a space measuring 15 feet wide by 20 feet long by 10 feet high is
300 square feet (length x width).

Answer 215

A

C. The volume of a space measuring 15 meters wide by 20 meters long by
3 meters high is 900 cubic meters (length × width × height).

Answer 216

A

• Client’s requirements: At least initially, spaces should be designed to focus on
the client’s needs, not the system’s needs.

• Client’s processes: Designers should learn the end users processes for activities they will conduct in the space.

• Client awareness: End users and/or clients do not always understand clearly what they want or need. Clients often have a general idea of what they want an AV system to do, but they may not actually know what is possible or practical to implement.

Answer 217

A

• Boardrooms

• Conference and meeting rooms

• Huddle rooms

• Training rooms, lecture theaters, and classrooms

• Auditoriums

• Divisible spaces

• Videoconference rooms

• Courtrooms

• Museums, galleries, and exhibition spaces

• Arenas, sports complexes, and stadiums

• Houses of worship and religious education centers.

Answer 218

A

• Accessibility

• Doors

• Ceiling height

• Windows

• Interior finishes

• Static display systems

• Lighting and light levels

• Sightlines

• Electrical power

• Grounding

• Phone and networks

• Wi-Fi

• Ventilation

• Structural mountings

• Acoustics

Answer 219

A

• Audience area

• Presenter area

• Control and/or projection area

Answer 220

A

• Visual

• Sound

• Ease of movement throughout the room

• Audience comfort

Answer 221

A

• Presenter workstation

• Presenter and equipment

• Power, voice, and data

• Sightlines

• Versatility

Answer 222

A

• Equipment space

• Heating and cooling

• Electrical power requirements

• Voice and data

• Signal cabling

• Task lighting

• Sound isolation

• Monitoring

Answer 223

A

• Reception area

• Phones/network access

• Break area or lounge

• Restrooms

•Beverage and food service

• Kitchen and vending area

• Breakout room

Answer 224

A

• The shape of the room

• The composition of walls and other materials in the room

Answer 225

A

A numerical measure of the color of a light source compared to the light from a standard glowing object. “White” light sources each have a different mix of the colors of the visible spectrum, and color temperature is expressed in Kelvins (K). Lower color temperatures, such as 2,000K, indicate the light source produces more light at the red/orange end of the spectrum, while higher color temperatures, such as 6,000K, indicate the source produces more light at the blue/green end of the spectrum.

Answer 226

A

A complete lighting device, composed of a light source, optics, and housing. This is often called a light fixture or simply a fixture.

Answer 227

A

A grouping of architectural lighting fixtures that illuminate the same area.

Answer 228

A

A set of lighting levels that combine to create a complete lighting “look” or picture.

Answer 229

A

A. The AV designer should evaluate the overall design to determine whether the audience can see and hear the presentation and that movement within the seating area will be comfortable.

Answer 230

A

C. The AV designer should determine whether the room meets the size, power, and HVAC requirements and provides other services needed for the AV system components.

Answer 231

A

C. The primary concern of the AV designer regarding HVAC systems at a client site is whether the HVAC system will interfere with AV system component placement or create excessive noise.

Answer 232

A

A. The primary concern when reviewing the acoustical environment within a client site is the level of ambient noise and reverberation that is present within the room.

Answer 233

A

B. For inspecting detailed images, such as graphics and engineering diagrams, calculations should be made using the online analytical decision-making tool to establish screen size, viewing distances, and the sizes of image content.

Answer 234

A

C. An HD display has an aspect ratio of 16:9, which is equal to multiplying the height by 1.7777 to determine the width. In this case, the screen height of 4 foot (1.2 meters) times 1.7777 results in a screen width of 7.11 feet (2.17 meters).

Answer 235

A

C. The typical primary concern for AV designers regarding projectors and screens is the impact of ambient light on the quality of the image. In this instance, since there are several windows in this space, ambient light will likely be a substantial issue.

Answer 236

A

C. In a projection environment, the contrast ratio of the image is most affected by the ambient light levels within the room.

Answer 237

A

D. When evaluating the proposed AC power supply to an AV control room, the AV designer should consider how much power is necessary to operate the AV system components, what non-AV equipment is on the same distribution board as the AV equipment, and which existing outlets are available for the AV equipment.

Answer 238

A

• Viewing cone

•Viewing angle

• Viewing distance

Answer 239

A

D. Sightline studies are used to determine which portion of the screen the audience will be able to see from each of the seating areas throughout a room.

Answer 240

A

A. Darker colors are better suited to reduce ambient light levels within a room.

Answer 241

A

A. The AV designer is typically mostly concerned with reducing the amount of noise generated by an operating HVAC system.

Answer 242

A

C. Building regulations or codes typically define the type of wiring used by the
AV system, in addition to other factors, such as mounting requirements.

Answer 243

A

• Project directories

• Contract scopes and roles

• Owner and end-user information

• Industry standards

Answer 244

A

• Owner and design manuals

• Codes and ordinances

• Industry standards

• Network architecture

Answer 245

A

• Technology trends

• End-user needs

• AV tasks and parameters

• Infrastructure issues

• IT issues

Answer 246

A

• Lighting

• Electrical

• Mechanical (both noise and heat)

• Acoustical

• Data/telecommunications

• Networking

• Structural

• Architectural (space plans, adjacencies, allocations, and other architectural issues)

• Interiors (finish requirements)

• Coordination of other trades with AV installation needs

• The budget impacts of these issues

Answer 247

A

• Opinion of probable cost: This term describes an early attempt to determine the cost of a system before there is enough detail in the design to produce a line-item estimate.

• Estimate: This implies that there is a more objective basis for the cost provided. It is an approximate calculation that includes a line-item analysis for equipment and labor (perhaps including taxes and other ancillary costs) and would be more accurate than an opinion of probable cost.

• Quote: This is a detailed and enforceable estimate. It should be provided and identified as a quote for an AV system only if the estimate is based on a concept design/program report and a detailed system design.

Answer 248

A

• Owners

• End users and technology managers

• Architect

• Project manager

• General/prime contractor

• AV integrator

• Other professionals with special interests

Answer 249

A

C. The program phase should focus on defining the user needs, the general AV systems required to meet these needs, and the general costs of these systems.

Answer 250

A

A. The AV system capabilities should be defined based on what the end users need to accomplish. This will ensure that the system meets the needs of the users.

Answer 251

A

A. The concept design/program report provides an overall description of the system, its capabilities, and general cost. Once it is reviewed and approved, it will provide the basis for more detailed descriptions of the AV system.

Answer 252

A

D. The end users who were consulted during creation of the program report are typically identified within the executive summary.

Answer 253

A

C. The opinion of probable cost is a general estimate of the overall cost of the AV system that can be used by the client as a basis for creating a general budget for the AV system portion of a project.

Answer 254

A

C. Once the AV concept design/program report is reviewed and approved, it will provide the basis for creating detailed AV design documents and cost estimates.

Answer 255

A

• Two-way or three-way, with passive crossover: These are usually cabinet units with multiple (typically two or three loudspeaker types included to cover the full range of hearing.

• Powered/Active: Often called powered or active loudspeakers, these have one or more crossover networks and amplifiers integrated within the loudspeaker cabinet.

• Constant-voltage (25V, 70V, and 100V): Also called a high-impedance speaker system, this method of distributing sound over a large area throush a network of speakers tends to minimize power loss.

• Subwoofers: Also known as sub-bass loudspeakers or simply subs, these are used to reproduce only the lowest acoustic frequencies. The subwoofer is a critical addition to a high-fidelity audio system.

• Clusters/Arrays: These are groups of loudspeakers used to cover a wide area.
Each speaker component of the cluster/array is directed to provide coverage to a section of the audience.

• Specialty: systems are designed to meet various situations, such as very narrow focused beams, or asymmetric coverage. Some can even be steered electronically to respond to a changing situation.

Answer 256

A

Echo-cancellation system

Answer 257

A

Total Impedance Zt = Z1 + Z2 + Z3

where:

• Zt equals the total impedance of the circuit.

• Z1 equals the rated impedance of the first loudspeaker.

• Z2 equals the rated impedance of the second loudspeaker.

• Z3 equals the rated impedance of the third loudspeaker, and so on.

If you have four loudspeakers, each rated at 4 ohms:

Z=4+4+4+4

Z = 16 ohms

Therefore, an amplifier rated for a 16-ohm load would be the best choice. An amplifier optimized for a 4-ohm load could not efficiently couple energy to this circuit of loudspeakers.

Answer 258

A

Zt=1/((1/Z1)+(1/Z2)+(1/Z3))

where:

• Zt equals the total impedance of the circuit.

• Z1 equals the rated impedance of the first loudspeaker.

• Z2 equals the rated impedance of the second loudspeaker.

• Z3 equals the rated impedance of the third loudspeaker, and so on.

Fortunately it is quite common for all of the loudspeakers in a parallel circuit to be rated at the same impedance. In that case, the impedance of the circuit equals the impedance of one of the loudspeakers divided by the total number of loudspeakers wired in parallel:

Total Impedance Zt = Z1/N

where:

• Zt equals the total impedance of the circuit.

• Z1 equals the rated impedance of one of the loudspeakers.

• N equals the number of loudspeakers wired in parallel.

If you have four loudspeakers wired in parallel, each rated at 8 ohms, the circuits impedance is 2 ohms.

Zt = 8/4

Answer 259

A

• Direct-coupled: A direct-coupled system (also called a low impedance system) is designed for low impedance loudspeakers (16 ohms, 8 ohms, or 4 ohms) and works pretty much as its name implies. The system loudspeakers are connected directly to a power amplifier output.

• Constant-voltage: When it becomes impractical to connect a large number of
loudspeakers in a direct-coupled scheme, its common to employ transformers. This setup is called a distributed or constant-voltage system. Constant-voltage systems are often identified by the maximum voltage allowable, such as 25V, 70V, or 100V.

Answer 260

A

• 1:1 transformer: This type of transformer has an equal number of primary and secondary windings. It is used for electrical (galvanic) circuit isolation to solve problems such as audible hum, buzz, or rolling hum bars on a display.

• Step-up transformer: This type has more windings on the secondary side than on the primary side. Voltage and impedance increase, while available current decreases.

•Step-down transformer: This type has fewer windings on the secondary side than on the primary side. Available current increases, while voltage and impedance
decrease.

Answer 261

A

dB - 20 log10 * (distance1 / distance2)

dB = 20 log(1 meter / 2 meters)

dB = 20 log(0.5)

dB = 20(-0.301)

dB = -6.02

Subtract final number from original dB output.

Answer 262

A

SPL increase = 10 log (power2 / power1)

6dB = 10 log(x / 1)

0.6 = log x

x = 3.98 watts

where:

• 6dB is the SPL increase required from the loudspeaker.

• x represents the power in watts required at the loudspeaker.

• 1 watt is the reference power input from the loudspeaker specification.

Answer 263

A

• Functionality

• Interoperability

• Interconnectivity

• Capabilities

Answer 264

A

• IP addressing

• Subnetting

• Virtual LANs (VLANs)

• Virtual private networks (VPNs)

• Directory integration

• Network security

Answer 265

A

• Audio Video Bridging (AVB):
Ethernet AVB is an IEEE standard that transports uncompressed video and up to 200 channels of 48kHz/24-bit audio in real time, plus embedded control and monitoring, using Ethernet frames. It requires special, AVB-enabled switches and network components but does not require separate network infrastructure or dedicated bandwidth.

• Dante: Over gigabit Ethernet (1Gbps), Dante transports up to 1,024 channels of 48kHz/24-bit audio; 512 channels at 96kHz/24 bit; or HDMI video including eight channels of audio. Over 100Mbps Ethernet, it can transport up to 96 channels of 48kHz/24-bit audio, or half that number at 96kHz/24 bit. Dante is fully routable over IP networks using standard Ethernet switches, routers, and other components. It requires no separate infrastructure.

Answer 266

A

Signal flow diagram

Answer 267

A

• Equipment rack elevations

• Specialized plates and panels

• Specialty connector and miscellaneous wiring diagrams

• Custom configurations and modifications

• Patch-panel layouts and labeling

• Custom application documentation

• User interface descriptions

Answer 268

A

A. The primary initial consideration of the AV system designer when designing a video display system component of an AV system is determining how the client will use the display system. This will drive the subsequent decisions about resolutions, screen size, screen location, and so on.

Answer 269

A

C. The AV designer should determine the needed monitoring, feeds, and recording requirements, and ensure that they are supported by the system design.

Answer 270

A

C. During the design stage of the AV system, the designer must have a clear understanding of the client needs, such as the media that the client must be able to present, and use this information to design a system that accommodates the necessary sources.

Answer 271

A

D. Since the system bandwidth is limited by the lowest bandwidth device within the system, the AV system designer should select components that maximize the bandwidth of the entire system.

Answer 272

A

D. The three main performance parameters that an audio system should be designed to achieve are loudness, intelligibility, and stability.

Answer 273

A

A. As with all AV system design decisions, the frequency response of an audio system should be based on the client needs and intended applications. For example, an audio system that will transmit only videoconferences does not need to achieve the same wide frequency response as a system intended to amplify music performances.

Answer 274

A

B. An echo canceler can reduce the echoes that sometimes impact the intelligibility of the audio portion of a videoconference.

Answer 275

A

C. When wiring loudspeakers in a series, the impedance is additive, meaning that three loudspeakers that each have 4 ohms of impedance will result in a system of 12 ohms of impedance.

Answer 276

A

B. Audio systems where the loudspeakers are located far from the amplifier typically use a constant-voltage loudspeaker system that includes transformers for each loudspeaker.

Answer 277

A

A. The formula used to determine the drop in acoustic energy if the user moves from 6 to 12 meters away from a sound source is dB = 20 log × (6 meters / 12 meters).

Answer 278

A

• Direct-connection termination

• Compression termination

• Soldering termination

• Crimping termination

• Linear-compression termination

• Insulation-displacement termination

Answer 279

A

• Stray wires that may produce short circuits

• Use of the correct wires at the appropriate contact points or pins

• Excessive or insufficient solder

• Sharp protrusions, extensions, or evidence of foreign matter

Answer 280

A

• Building the rack itself

• Installing the equipment

• Wiring the hardware together

Answer 281

A

Rack-elevation drawing

Answer 282

A

• Convection cooling: This type of cooling relies on the fact that hot air rises to move heat upward and out of vents at the top of the rack.

• Evacuation cooling: This type of cooling uses fans to draw hot air out of the rack, usually through top vents.

• Forced air cooling: This type of cooling uses an approach that’s the opposite of evacuation. It uses fans to force cool or even chilled air into the rack from below, and uses vents at the top of the rack to provide an exhaust for the hot air.

Answer 283

A

• In some cases, the first step in building an equipment rack is actually assembling the rack itself. It may come in many pieces that must be put together prior to placing electronic equipment inside.

• Install all rack mechanical accessories. These can include power and grounding strips, horizontal and vertical cable management systems, casters, and fans.

• Assemble the equipment to be mounted in the rack.

• Document any information, such as equipment serial numbers, to include in manuals you will provide to the client. Some serial numbers or product labels can be difficult to locate after the equipment is in the rack. Therefore, it’s important to gather this information before loading the rack.

• Install mounting ears on equipment where necessary. Mounting ears are metal brackets you attach to an AV component so that you can mount it in a rack. They could be optional accessories purchased from the equipment manufacturer, or they could be included with the equipment. Some AV equipment has built-in mounting ears.

• Identify the intended locations for specific components and install them in the 9 rack appropriately. Keep in mind that attempting to hold individual pieces of equipment in place while installing the mounting screws can be hard work. A as common best practice is to lay the rack on its back on top of a protective sheet so that the rack is not scratched or damaged.

• Fill all rack spaces with equipment, blanks, vents, or power strips, so that the space matches your rack-elevation drawing. Empty spaces can affect air flow.

• Fasten the equipment mounting ears to the rack rail using screws.

• Make all internal rack-wiring connections between equipment inputs and outputs and organize the cabling. Use the AV system block diagrams to determine the signal path through a system.

• Install the AC power components defined in the rack design documents and applicable codes and standards. This step may include configuring the system to access more than one AC power circuit, properly placing transformers (to allow for service access and minimize electrical interference), and ensuring proper grounding both for safety and to minimize the potential for hum.

Answer 284

A

• 1 cable = 53 percent
If you are running only one cable through a conduit, that
cable’s cross-sectional area may take up to 53 percent of the conduit’s internal cross-sectional area.

• 2 cables = 31 percent If you are going to run two cables inside a conduit, the sum of the two cables’ cross-sectional area may be up to 31 percent of the conduit’s internal cross-sectional area.

• 3 cables = 40 percent If you are going to run three cables through a conduit, the sum of the three cables’ cross-sectional area may be up to 40 percent of the conduit’s internal cross-sectional area.

Answer 285

A

• Improper calculation of loads

• Shear load, in which gravity pulls the mount down the wall, shearing off the bolts like a pair of scissors

• Tensile load, in which the load stretches the mounting fastener, causing soft, inferior grade fasteners (like bolts) to stretch, distort, or break

• Pull-out, which refers to the fastener pulling out of the structure, wall, or ceiling from which it is mounted

• Shock loading, which refers to a sudden additional load, such as from an earthquake or a person hanging from a mount

• Bolts placed at the top of the mount carry more stress than those placed at the bottom (since not all fasteners carry the same the load in a mount), although following the manufacturer’s instructions for placement should avoid this problem

Answer 286

A

Shear load

Answer 287

A

Tensile load

Answer 288

A

• DHCP: This approach allows network administrators to automate address assignment. When a device connects to the network, the DHCP service of server will assign an IP address to the device’s MAC address. The pool of available IP addresses is based on the subnet size and the number of addresses that have been allocated. DHCP is easy to manage because no two devices get the same address, relieving potential conflicts. It also allows more devices to connect to the network. However, with DHCP, you never know what a device’s IP address will be from connection to connection. Blocks of IP addresses can be omitted from the DHCP pool to use for statically addressed devices.

• Static IP addressing: This approach assigns fixed IP addresses to networked devices. Many AV devices must always have the same address so control and monitoring systems can find them. In the absence of a DHCP server, you will need to manually set the IP address (which you must obtain from the IT manager), hard-coding ic onto each device. To do this, you will need the IP address, the subnet mask, the device name, and the DNS server and gateway addresses.

• Reserve DHCP: This is a hybrid approach to IP addressing. Using reserve DHCP, a block of statically configured addresses can be set aside for devices whose IP addresses must always remain the same. The remaining addresses in the subnet will be assigned dynamically. To reserve addresses for AV devices, you need to list the MAC address of each device that requires a static address.

• DNS This approach uses a hierarchical, distributed database that maps easily remembered names to data such as IP addresses. A DNS server keeps track of all the equipment on the network and matches the equipment names so they can be easily located on the network or integrated into control and monitoring systems. Many AV devices don’t natively or fully support DNS address assignment.

Answer 289

A

A. Stray wires that extend outside the termination are a sign of an improper termination. A stray wire can cause a short that will interfere with system operation.

Answer 290

A

B. The AV technician should test continuity of the cable to determine whether it is properly transmitting signals or whether it is shorted in some manner.

Answer 291

A

A. An IP address is used to give each component on a TCP/IP network a unique address that allows components to communicate.

Answer 292

A

A. The metal rack casing and components can interfere with an RF signal transmitted from within a rack.

Answer 293

A

D. A ventilation approach that uses a fan to draw hot air from inside the rack is called an evacuation method.

Answer 294

A

A. Signal separation within a rack refers to grouping cables according to signal strength so that stronger signals will not create interference on cables carrying lower-level signals, such as power cables interfering with microphone cable signals.

Answer 295

A

A. Heavy equipment should be securely mounted, either using the building structural support elements or blocking installed behind the drywall specifically to be used as a mounting support.

Answer 296

A

A. Mounting plans for difficult mounting situations should be evaluated by a structural engineer familiar with the building’s structural elements.

Answer 297

A

C. The load limit rating refers to the weight at which the item will structurally fail. For example, the load limit on a flat-screen mount is provided to indicate the maximum weight that can be supported using the mount.

Answer 298

A

A. It’s true that HVAC systems can transmit vibrations that can adversely impact the quality of a projected image.

Answer 299

A

C. The permissible area refers to the amount of cable that can be run through a conduit, based on the outside cable diameter.

Answer 300

A

D. The installation team should review the system design to determine what equipment and materials are needed, along with the staff required to actually set up the system. It will also help the team determine how much time is required for system setup, which will aid in scheduling the installation tasks in a manner that meets the client deadlines.

Answer 301

A

A. Implementing a VLAN can be labor-intensive because its broadcast domain must be segmented on every switch in the network.

Answer 302

A

A. The AV team should strive to ensure that all microphones are mounted behind the loudspeakers to minimize any feedback.

Answer 303

A

C. You would place a projector with a 2.0 ratio lens 6 meters (20 feet) from the screen to create an image 3 meters (10 feet) wide.

Answer 304

A

D. The maintenance log should document all relevant maintenance actions in a manner that aids in ensuring the ongoing operation of the AV system.

Answer 305

A

C. Commissioning is a process that systematically evaluates the performance of the AV system and components and documents that the performance meets the identified standards.

Answer 306

A

A. Commissioning is intended to demonstrate that the installed AV system operates as intended.

Answer 307

A

D. Understanding signal flow will help an AV technician to determine the source of any problems or performance issues.

Answer 308

A

C. Guidance for AV system users should focus on the basics, such as how to display an image, control sound, and turn components on and off.

Answer 309

A

B. The proper shutdown procedure for an AV system is typically based on turning off components in a specific order to ensure that other components are not damaged by an improper shutdown sequence.

Answer 310

A

A. A detailed maintenance log provides valuable information that will aid in ongoing preventive maintenance.

Answer 311

A

D. End-user training will typically not address how to repair or maintain the
AV system.

Answer 312

A

E. The AV system documentation is typically composed of manufacturer manuals for all equipment. These contain instructions for the system’s operation and information about its design and configuration, including signal paths, to enable a technician to troubleshoot and correct any problems with the system.
The documentation should also detail the configuration of the control system, including DIP switch settings and IP addresses of individual components.
Additionally, the documentation should include basic operating instructions written for the AV knowledge level of the end user.

Answer 313

A

• Scope, which covers deliverables and activities that must be accomplished

• Time, including its estimation and duration

• Cost, for human and material resources

• Quality, to make sure performance meets expectations

• Risk, including threats, opportunities, and response strategies

Answer 314

A

Gantt Chart

Answer 315

A

C. The project budget is the amount of labor and materials allocated to perform the agreed-upon work.

Answer 316

A

A. The best approach is to document the changes and costs for the changes within a formal CO and have both the client and the company representative sign the CO to confirm that each side agrees to the changes to the original contract.

Answer 317

A

A. A dependency on a project task schedule refers to a task that cannot be started until another task has been completed. For example, the task of installing a painting walls have been completed.

Answer 318

A

C. The AV team should actively communicate and coordinate with both the project manager and other vendors to ensure that the AV installation is not impacted by other vendors working on the project.

Answer 319

A

C. An RFC is the appropriate document for the vendor to submit to the owner in the event that changes to the AV system installation contract are required

Answer 320

A

C. The WBS (work breakdown structure) defines project deliverables and relates the elements of work.

Answer 321

A

B. The most desirable approach is for the vendors and suppliers to become long. term partners with the AV company, with all parties striving to meet the dient needs.

Answer 322

A

D. The overall objective of managing stock and inventory is putting in place systems that will enable the manager to know the following:
• The equipment and supplies the company has on hand at any time
• The items that are on order and when they are expected to arrive
• The specific equipment and supplies that have been sent to client sites, either for temporary use to support an event or for installation at the site

Answer 323

A

A. A unique bar code or RFID tag placed on an equipment case or road case can be used to check that individual item of equipment in and out of a warehouse
or venue.

Answer 324

A

D. Ensuring security for the AV equipment is the responsibility of whoever has control of the equipment at the time. This can be the AV company staff, the client, the end user, or security personnel. It depends on the use of the equipment and at which point in the event or installation process security is required.

Answer 325

A

A. The key initial concern related to security and theft prevention for rental equipment is ensuring that you properly identify the person renting the equipment. This reduces the opportunity for theft resulting from fraud, such as someone providing a false identification in order to take possession of your equipment.

Answer 326

A

C. AV professionals should strive to keep up-to-date on the latest technology and practices by obtaining industry information from a wide range of sources, including courses, seminars, publications, vendor presentations, and professional certifications.

Answer 327

A

B. Remote-monitoring systems are typically used to track system usage, identity system or component failures, and identify any instances of tampering or removal of system components.

Answer 328

A

• Extension of manufacturers warranties

• Emergency and nonemergency service visits

• Preplanned schedule of preventive maintenance visits

Answer 329

A

• Replace system components that have limited, defined life cycles

• Calibrate or adjust system devices

• Physically adjust equipment

Answer 330

A

B. A service agreement is a type of maintenance agreement that commits an AV company to providing ongoing preventive maintenance for a client system.

Answer 331

A

C. A new AV device that fails within the first few weeks after installation is typically repaired as part of the manufacturer’s warranty.

Answer 332

A

A. The first step the AV technician should take when an AV system problem is reported is to obtain more information about the problem, such as the symptoms of the failure, so that the technician can begin to narrow down the cause of the problem.

Answer 333

A

C. The objective of preventive maintenance is to address system maintenance issues prior to a failure to ensure that the system continues to operate. In this case, replacing a projector bulb according to a schedule and prior to the failure of the bulb is preventive maintenance.

Answer 334

A

• Swapping

• Divide and conquer

• Divide the problem into subsystems

• Signal flow

Answer 335

A

D. The first step in the troubleshooting process is to clearly identify the failure
symptoms.

Answer 336

A

B. An intermittent failure is difficult to reproduce because it is not present all the time. This makes it hard for the technician to identify and isolate the problem.

Answer 337

A

A. Once the characteristics of the system failure are clearly identified, the next step is to examine the system to determine whether the problem is simple to address and, if not, gather more information that will aid in identifying possible faulty functions.

Answer 338

A

D. Often, the most efficient process for localizing the faulty function within a malfunctioning AV system is to logically divide the system in half, determine which portion has the failure, and then repeat for the failed half. Continue the process until the failure source is narrowed down to the faulty component.

Answer 339

A

C. The technician should consider user error when troubleshooting an AV system failure because some users do not understand how to properly operate the system. It’s possible that a user has changed a setting or performed another action that caused the failure.

Answer 340

A

D. The easiest method to test whether a failed microphone is the source of a system problem is to swap out the suspect microphone with a new microphone that you know is working and see whether the system works properly.

Answer 341

A

A. The brightness setting is not a typical reason for a video projector to overheat.

Answer 342

A

D. Cables and connectors fail more frequently than components. When cables and connectors are used on a regular basis and not handled carefully, they can be damaged and may present a variety of symptoms.

Answer 343

A

A. Adding compression to the microphone signal chain will not address feedback. The best practices for controlling feedback include keeping the microphone as close to the sound source as possible, keeping the loudspeakers in front of and as far from the microphones as possible, appropriately positioning the volume (gain), and turning down or muting all unused microphones.

Answer 344

A

A. Poor gain structure is a typical source of a constant high-frequency hiss in the system. This is because of the inputs on the mixer being set too low and subsequent stages having their gain increased in an attempt to compensate.

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