Week 27 Chapter 13 Part 1 - Pages 13-1 to 13-37

Question 1

When describing digital video signal standards, the serial digital interface (SDI) is for one-way serial transmission of video and audio over _____ cable.

a. Optical fiber
b. Coaxial
c. Shielded twisted-pair
d. Unshielded twisted-pair

Answer 1

b. Coaxial

p 13-24

SDI is for one-way serial transmission of video and audio over standard RG59 or Series-6 coaxial cable. SDI uses BNC connectors (see Table 13.4).

Question 2

When describing digital audio signal sampling, _____ is defined as the range of numbers that can be assigned to each sample.

a. Quantization noise
b. Bit depth
c. Resolution
d. Granularity

Answer 2

c. Resolution

p 13-13

The resolution of a digital audio signal is the range of numbers that can be assigned to each sample.

Question 3

When describing digital audio signal sampling, _____ is affected by the sampling rate and the signal amplitude

a. Quantization noise
b. Bit depth
c. Resolution
d. Granularity

Answer 3

d. Granularity

p 13-14

Granularity is affected by the sampling rate and the signal amplitude; the lower the granularity, the better the signal quality.

Question 4

When using higher sampling rates to digitally represent the analog signal amplitude and frequency, the error between the actual analog signal value and the digitized value is called ___

a. Quantization noise
b. Bit depth
c. Resolution
d. Granularity

Answer 4

a. Quantization noise

p 13-13

This error is known as quantization noise.

Question 5

For video applications that do not require perception of text or detailed images, a factor of up to ___ may be used, which allows for a smaller image size or longer viewing distances.

a. 4
b. 6
c. 8

Answer 5

c. 8

p 13-31

An image detail factor of 6 is typically used for tasks that require some detail but do not include reading of small fonts. For tasks requiring finer detail and smaller font reading, a factor of 4 may be used increasing the minimum screen height.

Question 6

Human perception of light is most sensitive to the ___ spectrum of light

a. Red / yellow
b. Green / blue
c. Blue
d. Red
e. Yellow / green

Answer 6

e. Yellow / green

p 13-19

Human perception of light is most sensitive to the yellow/green spectrum of light, less sensitive to red, and least sensitive to the blue spectrum.

Question 7

When describing the properties of sound, the action of molecules ___ is called rarefaction

a. Exerting pressure
b. Vibrating
c. Compression
d. Moving apart

Answer 7

d. Moving apart

p 13-2

The action of molecules pressing closer together is called compression. The action of the molecules moving apart is rarefaction. The changes in pressure among these molecules create invisible sound waves.

Question 8

When describing digital video signal standards, the serial digital interface (SDI) can operate over a maximum cable length of _____ at a bit rate of 270 Mb/s.

a. 300 m (984 ft)
b. 100 m (328 ft)
c. 15 m (50 ft)
d. 3 m (10 ft)

Answer 8

a. 300 m (984 ft)

p 13-24 Table 13.4

Any rate greater than 1 Gb/s can operate over a maximum cable length of ≈ 100 m (328 ft)

Question 9

When describing control panel standards for audiovisual (AV) systems, IEEE 1394 requires devices to be within _____ of their connection.

a. 9 m (30 ft)
b. 7.6 m (25 ft)
c. 4.6 m (15 ft)
d. 3 m (10 ft)

Answer 9

c. 4.6 m (15 ft)

p 13-29

IEEE 1394 requires that devices be within ≈4.6 m (15 ft) of the connection or bus socket on a computer or other device.

Question 10

When describing digital audio signal sampling, the _____ the granularity, the better the signal quality.

a. Higher
b. Lower

Answer 10

b. Lower

p 13-14

Granularity is affected by the sampling rate and the signal amplitude; the lower the granularity, the better the signal quality.

Question 11

A full bandwidth RGB signal with horizontal sync and vertical sync, has the highest quality and stability and requires _____ cables to carry the signal.

a. Five
b. Four
c. Three
d. Two

Answer 11

a. Five

p 13-18 & Figure 13.13

RGB, horizontal sync, and vertical sync:
––Referred to as full bandwidth RGB with separate sync
––Highest signal quality and stability
––Requires five cables to carry the signal, one for each component

Question 12

Most audio equipment operates in an audio range larger than that of the human ear, typically 10 Hz to 30 kHz.

a. True
b. False

Answer 12

a. True

p 13-10

Question 13

When describing control panel standards for audiovisual (AV) systems, IEEE 1394 supports _____ modes.

a. Synchronous and asynchronous
b. Isochronous and synchronous
c. Asynchronous and isochronous

Answer 13

c. Asynchronous and isochronous

p 13-29

IEEE 1394 supports asynchronous and isochronous modes. The isochronous mode, which delivers data at a guaranteed rate, reducing the need for buffering, is ideal for applications such as real-time video.

Question 14

AV communications signals are controlled by a variety of control protocols. The most common version of serial communication is classified as:

a. SDTV
b. TCP/IP
c. RS-422
d. RS-232

Answer 14

d. RS-232

p 13-26

This is a form of data communications where information is sent sequentially, one piece at a time, down a cable. The most common version of serial communication is classified as RS-232.

Question 15

In a cathode ray tube (CRT) display, the horizontal (H) sync pulse communicates to the electron beam charging the phosphors to turn itself off at the end of each line; a process called horizontal:

a. Cycling
b. Retrace
c. Tracing
d. Blanking

Answer 15

d. Blanking

p 13-16

The electron beam charges the phosphors in a line from left to right. The beam then drops down and scans another line. At the end of each line, the horizontal sync pulse communicates to the beam to turn itself off, which constitutes a process called horizontal blanking.

Question 16

In a(n) _____ vision seating layout, the vertical sight-line of a viewer passes over the heads of the persons in the first row ahead.

a. Aligned-row
b. Sloped-row
c. Alternating-row
d. Single-row

Answer 16

d. Single-row

p 13-34

Typical sightline techniques include single-row vision and double-row vision seating layouts. In single row vision, the vertical sightline of a viewer passes over the heads of the persons in the first row ahead, as illustrated in Figure 13.20.

Question 17

The dBu unit used to measure audio system voltage is referenced to _____ across any impedance.

a. 1 V
b. 0.775 V
c. 1 mV
d. 0.775 mV

Answer 17

b. 0.775 V

p 13-11 Table 13.2

Question 18

When describing digital video signal standards, _____ is the version of video compression tools typically used for digital TV signal transmission.

a. MPEG-4
b. MPEG-3
c. MPEG-2
d. MPEG-1

Answer 18

c. MPEG-2

p 13-25

It is named after the international group that established it to standardize compressed video and audio. The version typically used for TV is MPEG-2.

Question 19

In analog video signaling, RF video is the combination of _____ video with _____ audio channels.

a. Component; two
b. Component; one
c. Composite; two
d. Composite; one

Answer 19

c. Composite; two

p 13-21

RF signals have the lowest video quality. RF video is composite video with two audio channels (see Figure 13.14).

Question 20

You are designing a four story retail mall and multiple sound systems within it. Which system should you design to support general music programming within common retail areas?

a. Distributed paging
b. Life safety
c. Sound masking
d. Sound reinforcement and playback

Answer 20

d. Sound reinforcement and playback

Question 21

A space has all hard surfaces including architecture and furnishings. The audio programming produced from the distributed sound system has become unintelligible. Which of the following will NOT mitigate the problem?

a. Add tapestries to the walls.
b. Provide additional speakers at lower output.
c. Increase the volume to the existing speakers.
d. Reduce the distance of the existing speakers to the listener.

Answer 21

c. Increase the volume to the existing speakers.