Understanding the Digital Domain

Question 1

What was the first type of switch used within computers?

Answer 1

Vacuum tube

Question 2

_____ law states that the number of transistors on an integrated circuit doubles every 18 months.

Answer 2

Moore’s

Question 3

Alternative name for an integrated circuit

Answer 3

Chip

Question 4

The power of a modern computer is essentially governed by the number of ____

Answer 4

Transistors

Question 5

Who was the co-founder of Intel?

Answer 5

Gordon Moore

Question 6

What type of signal varies smoothly and continuously over time?

Answer 6

Analog signal

Question 7

There are a(n) _____ number of signal values within an analog signal.

Answer 7

Infinite

Question 8

What term refers to a countable number of measurements?

Answer 8

Discrete

Question 9

Which of the following are examples of analog devices?
A) mercury thermometer
B) traditional camera(film camera)
C) videocassette(VHS or Betamax)
D) all of the above

Answer 9

D) all of the above

Question 10

Which of the following are examples of digital devices?
A) mercury thermometer
B) traditional camera
C) computer
D) both b and c

Answer 10

C) computer

Question 11

The duration of pulses within a signal is also called the ____ and is measured in terms of seconds.

Answer 11

Bit period

Question 12

Bit period and ____ are inversely related to each other.

Answer 12

Data rate

Question 13

A 6.5MB digital file stored on a hard disk contains ____ bits.

Answer 13

54,525,952

Question 14

A 2.5KB digital file contains ____ bits.

Answer 14

20,480

Question 15

In digital systems, ____ can be effectively filtered out if it’s level is not too great.

Answer 15

Noise

Question 16

Digital information, especially digital images and movies, is highly amenable to ____ because it contains an abundant amount of repetition.

Answer 16

Compression

Question 17

What form of energy may be used to transport bits efficiently over a wireless communication system?

Answer 17

Radio frequency

Question 18

Which of the following are examples of transmission cables?
A) copper wire
B) fiber optic cable
C) air
D) all of the above

Answer 18

D) all of the above

Question 19

Which of the following are examples of transmission media used to transport electrical signals?
A) copper wire
B) fiber optic cable
C) none of the above
D) both a and b

Answer 19

A) copper wire

Question 20

Which of the following is a measure of electricity?
A) degrees celsius
B) volts
C) seconds
D) all of the above

Answer 20

B) volts

Question 21

Calculate the data rate if the bit period of a signal is 0.4 microseconds.

Answer 21

2.5Mbps

Question 22

Calculate the data rate if the bit period of a signal is 0.0000005 seconds.

Answer 22

2 Mbps

Question 23

Calculate the bit period of a signal if the data rate is 2.5 Kbps

Answer 23

0.0004 seconds

Question 24

What multiplier has a value of 1,000,000 within context of transmission?

Answer 24

Mega

Question 25

Which multiplier has a value of 1,048,576 within context of storage?

Answer 25

Mega

Question 26

Calculate how many bits there are stored in an 8 KB digital audio file.

Answer 26

65,536 bits

Question 27

Calculate how many Megabytes there are in 41,943,040 bits.

Answer 27

5 MB

Question 28

A digital video system uses a display format of 1024 by 767 pixels. Each pixel is coded using 32 bits. The system uses AC current line (60Hz) for synchronization so the refresh rate is 60 screens/sec. What is the minimum size of the video memory, given in Gigabytes(GB), required to store one second of video? Assume no compression is used. Round to nearest hundredth decimal.

Answer 28

0.18GB

Question 29

``` Which of the following are classified as optical storage media? A) hard disk B) CD C) DVD D) both b and c ```

Answer 29

D) both b and c

Question 30

``` Which of the following are classified as magnetic storage media? A) hard disk B) floppy disk C) DVD D) both a and b ```

Answer 30

D) both a and b

Question 31

Which of the following are advantages of the digital domain? A) ability for noise removal B) vulnerability to the addition of noise C) ability for compression D) both a and c E) none of the above

Answer 31

D) both a and c

Question 32

``` Which of the following is a technique that may be used to manage errors within digital communication systems? A) compression algorithms B) encryption algorithms C) error control schemes D) both b and c ```

Answer 32

C) error control schemes

Question 33

When music is recorded on a CD, a digital recording device samples the sound 44,100 times per second. Each sample is 2 bytes(16 bits) long, and a separate sample is taken for each of the two speakers in a stereo system. Therefore each second of sound on the CD requires ______ bytes of memory.

Answer 33

176,400

Question 34

If an analog signal has frequency components up to 25,000 Hz, what would be the minimum sampling rate to satisfy Nyquist Law?

Answer 34

50,000

Question 35

In April 1989, Intel announced the introduction of the Microprocessor 80486 as the most advanced high performance Integrated Circuit thus far. It uses close to one million transistors. According to Moore’s Law, what was the closest to date it was expected to reach two million transistors circuits?

Answer 35

October 1990

Question 36

The output voltage of a certain device that uses CMOS family of IC’s is measured to be 1.6 Volts on a maximum of 3 Volts. This output will correspond to a logic value of ____.

Answer 36

Undefined

Question 37

Data compression ratio is defined as the ratio between the uncompressed size and compressed size, thus a representation that compresses a 20MB file to 5MB has a compression ratio of ____

Answer 37

4:1

Question 38

If a given signal contains frequencies up to 300 KHz, using Nyquist Law, the slowest we can sample this signal is ____

Answer 38

600 KHz

Question 39

An old RAM memory chip has 10,240 bytes. The size of the memory in Kbytes is _____

Answer 39

10 Kbytes