Unit 2 : Data Representation

Question 1

What is the goal of a computer representing data?

Answer 1

1. Represent enough of the real world data to satisfy our computational needs and our senses of sight and sound

Question 2

List out 2 ways for representing information

Answer 2

1. Analog
2. Digital

Question 3

What is analog data?

Answer 3

1. Analog data is a continuous representation, analogous to the actual information it represents

Question 4

What is digital data?

Answer 4

1. It is a discrete representation, breaking the information up into separate ( discrete ) elements

Question 5

Can computer work with analog data?

Answer 5

1. It cannot work with analog information directly without the digitise process ( changing data to 0 and 1 )

Question 6

How can we digitalise the analog information?

Answer 6

1. It was done by breaking the analog information into pieces and representing those pieces using binary digits

Question 7

Will electronic signals ( analog and digital ) degrade as they move down a line?

Answer 7

1. Yes

Question 8

What will happen when an analog signal digrades?

Answer 8

1. Information is lost

• Because any voltage level within the range is valid, it is impossible to know that the original signal was even changed

Question 9

What will happen when an digital signal degrades?

Answer 9

1. We can still retrieve the infrormation form a readonably degraded digital signal

• No information is lost as long as it is reclocked and regain its original shape before too much degration

Question 10

What is the difference between the representation of analog and digital data?

Answer 10

1. Analog - Continuous Waveforms
2. Digital - Binary Values

Question 11

What is the difference between the nature of analog and digital data?

Answer 11

1. Analog - Continuous
2. Digital - Discrete

Question 12

What is the difference between the signal type of analog and digital data?

Answer 12

1. Analog - Change over time ( Vary smoothly over time )
2. Digital - Have distinct levels

Question 13

What is the difference between the accuracy of analog and digital data?

Answer 13

1. Analog - More accurate representation of real-world data
2. Digital - Less accurate but easier to process

Question 14

What is the difference between the storage of analog and digital data?

Answer 14

1. Analog - Typically stored on analog device ( vinyl )
2. Digital - Stored digitally in binary format ( SSD )

Question 15

What is the difference between the processing of analog and digital data?

Answer 15

1. Analog - Required analog circuits for processing
2. Digital - Processed by digital circuits and computers

Question 16

What is the difference between the conversion of analog and digital data?

Answer 16

1. Analog - Requires Analog-to-Digital ( ADC ) and Digital-to-Analog ( DAC ) converters for used in digital systems
2. Digital - Does not require conversion if already digital

Question 17

What is the difference between the transmission of analog and digital data?

Answer 17

1. Analog - Degrades over long distances
2. Digital - Can be transmitted over long distances with minimal degration

Question 18

Was early computer binary? If no, it was what ?

Answer 18

1. No, it was decimal

Question 19

List out the early computer that uses decimal ( 2 )

Answer 19

1. Mark I
2. ENIAC

Question 20

How many values does boolean logic consists?

Answer 20

1. 2

• True / False
  On / Off
  Yes / No
  1 / 0

Question 21

Who proposed binary data processing?

Answer 21

1. John von Neumaan

Question 22

What are the benefits of binary data processing ( 2 )

Answer 22

1. Simplified computer design
2. Used for both instructions and data

Question 23

What is decimal , binary , octal and hexadecimal also call as?

Answer 23

1. Base 10 ( 0 - 9 )
2. Base 2 ( 0 and 1 )
3. Base 8 ( 0 -7 )
4. Base 16 ( 0 - 9 , A - F )

Question 24

What is 8 bits equal to?

Answer 24

1. 1 byte

Question 25

How many bytes does a word consists?

Answer 25

1. 4 bytes

Question 26

How to calculate from base 8 to base 10

Answer 26

1. Find out how many place ( 624 has 3 places )
2. Assign power to 8 according to the place ( 3 places so have 8^2 , 8^1 , 8^0 )
3. Evaluate ( 6 x 8^2 , 2 x 8^1 , 1 x 8^0 )

Question 27

How to calculate from base 16 to base 10

Answer 27

1. Find out how many place ( 6704 has 4 places )
2. Assign power to 16 according to the place ( 4 places so have 16^3 , 16^2 , 16^1 , 16^0 )
3. Evaluate ( 6 x 16^3 , 7 x 16^2 , 0 x 16^1 , 4 x 16^0 )

Question 28

How to calculate from base 2 to base 10

Answer 28

1. Find out how many place ( 010 has 3 places )
2. Assign power to 2 according to the place ( 3 places so have 2^2 , 2^1 , 2^0 )
3. Evaluate ( 0 x 2^2 , 1 x 2^1 , 0 x 2^0 )

Question 29

What is the formula for possible numbers?

Answer 29

1. R = B^K

R - Range
B - Base
K - Number Of Digits

• Example:
  1. Base 10, 2 digits
  R = 10^2 ( 100 )

2. Base 2, 16 digits
   R = 2^16 ( 65536 or 64K )
   - 16 bit PC can store 64K different number values

Question 30

What will happen when the base was larger ( 2 )

Answer 30

1. The more symbols required
2. Fewer digits needed

Question 31

How can we calculate from base 10 to base 2

Answer 31

1. List out base 2 required digits ( 42 means until 5 digits 100000 - 32 )
2. Divide the value ( 42 / 32 )
3. IF has reminder , write 1, no reminder, write 0
4. Continue the step until finish

Question 32

How to calculate from base 10 to base 16

Answer 32

1. List out base 16 required digits ( 5735 means until 4 digits 16^3 still 4096, 16^4 65536 )
2. Divide the value ( 5735 / 4096 = 1 reminder )
3. If has reminder, write 1 or the respected value, or write 0
4. We need to minus the value from what we divided ( 5735 - 4096 = 1639 )
5. Use the minus value to divide the value ( 1639 / 256 ( 16^2 ))
6. Repeat

• Minus value also needs to multiply the reminder
  if ( 1639 / 256 = 6 ), we need to minus like this 1639 - 1536 ( 6 x 256 )