Analog and Data

Question 1

What is information?

Answer 1

Knowledge we want to record or transmit

Question 2

What is a signal?

Answer 2

some means to record or transmit data or information

Question 3

What are examples of signals?

Answer 3

voltage, current, handwritten note

Question 4

What are the 2 types of Information?

Answer 4

1. Inherently continuous
2. Inherently discrete

Question 5

What does inherently continuous refer to?

Answer 5

infinitely many values

Question 6

What does inherently discrete refer to?

Answer 6

a finite number of values in any range

Question 7

What are examples of inherently continuous?

Answer 7

• mass
• temperature
• most other physical quantities
• blood pressure

Question 8

What are examples of inherently discrete?

Answer 8

• days in a week
• current study term
• names of the cities
• number of steps walked

Question 9

What are the 2 main ways to represent information?

Answer 9

1. Analog data
2. Digital data

Question 10

What kind of representation is analog data?

Answer 10

continuous representation

Question 11

What kind of representation is continuous data?

Answer 11

discrete representation using a finite number of digits or symbols

Question 12

What are examples of analog data?

Answer 12

thermometer

Question 13

What are examples of discrete data?

Answer 13

digital clocks, speakers

Question 14

What are the 2 methods for converting analog to digital data?

Answer 14

1. Sampling (discretization)
2. Quantization (truncation)

Question 15

What does sampling do?

Answer 15

converts continuous variations to discrete snapshots

Question 16

What does quantization do?

Answer 16

converts an infinite range of values to a finite one

Question 17

What is an example of going from analog data to digital data?

Answer 17

• digitalization of video by using the still frames and dividing the picture into pixels

Question 18

What is the Nyquist-Shannon sampling theorem?

Answer 18

The sampling rate must be at least >2x the original frequency component of the signal

Question 19

What are the 2 ways we can prevent information from being lost when we convert from analog to digital?

Answer 19

1. Nyquist-Shannon sampling theorem
2. Quantization error models

Question 20

What is the Quantization error models?

Answer 20

represent the difference between an original analog signal and its quantized digital representation

Question 21

What is the basic representation for digital data?

Answer 21

binary digit using the symbol “b”

Question 22

One bit holds a valve of what?

Answer 22

0 or 1

Question 23

How many bits are in a byte?

Answer 23

8

Question 24

Does DVD use decimal or binary systems?

Answer 24

decimal

Question 25

Does CD use decimal or binary systems?

Answer 25

binary

Question 26

Do computers work well with analog data?

Answer 26

No, they use digital data by breaking it down into discrete samples and then quantizing the values to approximate numbers

Question 27

What are some benefits of digital signal transmissions and storage?

Answer 27

- Digital signals have only a high or low state (0,1) - Analog has continuous values which will fluctuate in ranges

Question 28

What is the transmission medium?

Answer 28

The level of the signal fluctuation will be due to the noise produced by external effects

Question 29

True or False FOR ANALOG DATA: Degradation of analog signals is permanent; there is no way to determine if the distortions were present beforehand

Answer 29

True

Question 30

True or False FOR DIGITAL DATA: If the distortion is small enough, it can completely regenerate the signal and regain in original shape

Answer 30

True

Question 31

What are the benefits of digital storage and compression?

Answer 31

Both analog and digital data can be recorded - Digital copies are always completely identical to the original - Error-detection and correction codes exist for digital data - Compression (data redundancy removal) is much easier with mathematical algorithms that work with discrete values

Question 32

True or False Digital data is easier to produce, transmit, can be regenerated and is easier to store and compress

Answer 32

True