Chapter 2: Understanding the Digital Domain Key
1. Any piece of text may be represented as a sequence of bits.
2. Any piece of digital music may be represented as a sequence of bits.
3. The vacuum tube was invented after the transistor.
4. The transistor is classified as an electronic switch.
5. An integrated circuit is basically comprised of a group of transistors interconnected to each other.
6. Vacuum tubes may also be used in audio amplifiers.
7. An integrated circuit is comprised of millions of vacuum tubes.
8. An integrated circuit may include a thin layer of semiconductor material.
9. The size of a transistor today is on the order of a few centimeters.
10. Gordon Moore was the founder of Dell Inc.
11. Moore’s Law states that the number of transistors on a chip will triple every 18 months.
12. Moore’s Law is expected to reach its limit in the future.
13. Information that we receive in the natural world is in analog format.
14. After sampling the analog signal, the sample values are rounded off to the nearest available value during the
analog-to-digital conversion process.
15. The sampling and rounding off phases of the analog-to-digital conversion process does not result in any loss
of information from the original analog signal.
16. The rounded off samples resulting from the rounding off phase of the analog-to-digital conversion process
are assigned a binary code.
17. Audio digitizers are found within cell phones. They implement the analog-to-digital conversion process of
audio signals.
18. Digital cameras and scanners convert analog images into digital.
19. A DVD player is classified as an analog device.
20. A video cassette player is classified as a digital device.
21. Bits are physically transmitted as electrical signals over a copper wire.
22. Information is carried via electrical signals across a fiber optic cable.
23. Information is carried via radio frequency signals within satellite communication systems.
24. An example of a transmission medium that is used to carry optical signals is fiber optic cable.
25. The larger is the bit period, the smaller is the data rate.
26. If the bit period is 0.0005 seconds, 2000 bits per second may be transmitted over a transmission medium
with a basic signaling scheme.
27. 25,000 bps are the maximum transmitted across a transmission medium with a data rate of 25 Mbps.
28. A data rate of 1Gbps is equivalent to transmitting 1,000,000,000 bps.
29. Punch cards are an example of mechanical storage technology.
30. A hard disk is classified as an optical storage medium.
31. Bits are physically stored on optical storage media by creating small domains with different reflective
properties.
32. Flash memory is classified as an example of electronic storage.
33. One Byte is equivalent to 16 bits.
34. There are 3,000 bytes worth of digital information within a 3KB digital file stored on a CD.
35. A CD with a storage capacity of 700 MB is able to store 5,872,025,600 bits.
36. One advantage of the digital domain is its amenability to compressing digital information.
37. Any effect that interferes with the signal that carries the information can be classified as noise, whether the
information is being transmitted or stored.
39. Efficient error control schemes may be used within digital systems to detect and sometimes even correct
errors if they occur.
40. Encryption is a process that enables the detection and correction of errors within digital systems.
41. Digital information is stored more reliably and reproduced with greater ease compared to analog
information.
42. A digital receiver within a communication system has a much simpler task compared to an analog receiver
because it just needs to keep track of a finite number of signal values.
43. An integrated circuit is basically comprised of a large number of electronic switches called
____________________.
44. The ____________________ was the predecessor to the transistor.
45. The processing power of a digital device is essentially governed by the number of ____________________
and by how fast they can be turned on and off.
46. A(n) ____________________ is a device that was used within early computers and resembles a light bulb.
47. One problem with vacuum tubes is that they are ____________________.
48. ____________________ law states that the number of transistors on an integrated circuit doubles every 18
months.
49. There are a(n) ____________________ number of signal values within an analog signal.
50. Analog-to-____________________ converters are devices that convert analog signals to digital.
51. When converting an analog signal to digital, capturing as much of the original information as possible
requires a large number of ____________________.
52. An analog signal varies ____________________ over time.
53. Each sample needs to be ____________________ off to its nearest value before assigning a binary code to
each sample during the analog-to-digital process.
54. A(n) ____________________ is classified as a digital device.
55. Universally, a(n) ____________________ refers to the variation of a form of energy such as electricity or
light.
56. In many instances, signals require physical media called ____________________to carry them from one
point to another.
58. The duration of pulses within a signal is also called the ____________________ and is measured in terms
of seconds.
59. Bit period and ____________________ are inversely related to each other.
60. ____________________ is expressed in terms of bits per second (bps)
61. The smaller the bit period, the higher the ____________________.
62. Mbps is short for ____________________.
63. The acronym used to express Gigabits per second is ____________________.
64. The terms kilo, mega, giga, etc. are examples of multipliers used to express ____________________
numbers.
66. Light that is used to read bits from the surface of a CD is emitted from a ____________________.
68. A 1MB digital file stored on a hard disk contains ____________________ bits.
69. A 2KB digital file stored on a CD contains ____________________ bits.
70. One byte is equal to ____________________ bits.
71. In IT,____________________ is defined as an effect that disrupts information—an unwanted occurrence
that interferes with a signal and hence the information carried by the signal.
72. In digital systems, ____________________ can be effectively filtered out if its level is not too great.
73. A ____________________ signal is comprised of only a finite number of signal values.
74. Noise can be removed by passing a noisy signal through an electronic device that is set at a certain
____________________.
75. Special ____________________ schemes are applied to detect and sometimes even correct errors when
they occur.
76. If the receiving end of a digital communications system detects an error within the received bit stream, it has
the option of requesting that the information be ____________________ by the transmitting end.
77. Digital information can be transmitted and processed at a much faster rate than ____________________
information.
78. Miniaturization of transistors, the development of novel materials, and more refined manufacturing
techniques for integrated circuits enable faster ____________________.
79. ____________________ ensures that if third parties intercept information-carrying signals, they cannot
decipher what is carried over these signals.
80. Digital information, especially digital images and movies, is highly amenable to ____________________
because it contains an abundant amount of repetition.
81. Applying an assortment of ____________________ algorithms to binary streams can achieve varying
degrees of compression.
82. Analog storage approaches are highly susceptible to degradation because of aging and environmental
factors, so ____________________ storage formats are usually preferable.
83. Information on digital media such as flash drives can be reproduced with the ____________________
quality as the original, and with greater ease.
84. Transmitters that have to transmit analog signals must be able to generate a signal with an
____________________ number of values, and the receiver has to follow this complex signal.
85. Which of the following was the first type of switch used within computers?
A. Transistor
86. Which of the following is the alternative name for an integrated circuit?
87. Moore’s Law states that the number of transistors ____ every 18 months.
88. The power of a modern computer is essentially governed by the number of ____.
89. Who was the co-founder of Intel?
90. Which type of signal varies smoothly and continuously over time?
91. Which of the following is a device that can capture analog sound and generate an analogous electrical
signal?
92. Which of the following is a term that refers to a countable number of measurements?
93. Which of the following are examples of analog devices?
94. Which of the following are examples of digital devices?
95. Which form of energy may be used to transport bits over a wireless communication system?
96. Which of the following are examples of transmission media?
97. Which of the following are examples of transmission media used to transport electrical signals?
98. Which of the following is a measure of electricity?
99. Calculate the data rate if the bit period of a signal is 0.0001 s.
100. Calculate the data rate if the bit period of a signal is 0.00000005 s.
101. Calculate the bit period of a signal if the data rate is 25 Kbps.
102. Which of the following multipliers has a value of 1,000,000 within the context of transmission?
103. Which of the following multiplier has a value of 1,000,000 within the context of storage?
104. Calculate how many bits there are stored in a 4 KB digital audio file.
105. Calculate how many Megabytes there are in 41,943,040 bits.
106. Which of the following are classified as optical storage media?
107. Which of the following are classified as magnetic storage media?
108. Which of the following are advantages of the digital domain?
109. Which of the following is a technique that may be used to manage errors within digital communication
systems?
110. Explain how the transistor enabled the emergence of the digital age.
Several fundamental advantages of representing information using only ones and zeros exist. However, unless
111. Discuss the analog-to-digital conversion process.
112. Discuss the tradeoffs involved in the analog-to-digital conversion process between cost and quality.
113. Discuss the types of transmission media and the type of energy the signals need to exist in, to be able to be
114. Explain the physical fundamental differences in storing bits on the various types of storage media.
115. Discuss how error control may be achieved within a digital communication system.
116. Discuss how encryption may be able to protect sensitive information transmitted along a transmission
medium.
117. Explain why digital information reproductions are usually of higher quality than their analog counterparts.
118. Explain how noise may be removed from a noisy digital signal.