Data Representation Flashcards
What component processes data in a computer?
Logic gates
Where is data in a computer stored temporarily?
A register
What is the range of the hexadecimal number system?
0-9 and A-F
Convert 13 to binary.
1101
What is the maximum binary length?
16-bits
Convert 10010110 t denary and hexadecimal.
150 denary
96 hexadecimal
Convert 01100011 to denary
99
Are there decimals in number systems?
No.
Convert 201 base 10 to hexadecimal.
C9
Why must all data be converted to binary when going into a computer?
A computer can only process binary data.
Convert 5E to denary
94
Convert A2 to a binary number
10100010
How is the use of hexadecimal beneficial? [3]
- it is a shorter way of representing binary.
-it is easier for humans to understand than binary. - it is easier to debug and locate errors in data.
Where is hexadecimal used in computer science? [4]
- ASCII/Unicode
- MAC address
- IP address
- representing colour values in HTML/CSS
- assembly language
Add 10010100 to 00011110.
10110010
Why can computers only use binary?
Computers only understand binary data which uses 1’s and 0’s rather than analogue data.
When does an overflow error occur?
An error that occurs when a number larger than a register can store is generated/returned.
How does the computer know the largest amount of bits it can store?
It has a predefined limit.
What is the effect of one logical shift to the left?
The number is multiplied by 2.
What is the effect of a logical shift to the right?
The number i divided by 2.
What happens to the empty space created after a logical shift?
It is filled with a 0.
What is one problem with logical shifts?
The most/least significant bit is lost so the data can loose its integrity (real value).
Multiply this by 4. 11101100.
How did you do this?
10110000
Done using two logical shifts to the left.
What is two’s complement?
A method used to represent negative binary numbers.
What are the steps of two’s complement? [2]
- get a binary number (if decimal convert it)
- invert all the values in the binary number
- add 1 to your result
Convert -25 base 10 to binary using two’s complement.
11100111.
How do i know if my binary value is negative?
If the most significant bit is 1.
Convert this negative binary to a two’s complement 8-bit integer.
10100110.
-90
Conver 25 to a two’s complement 8-bit integer.
00011001
Why can a computer not understand the alphabets?
A computer only processes binary, so all data must be converted to binary.
Which character set is more preferred between ASCII and Unicode?
Why?
Unicode. It has a greater range of characters and symbols including different languages and emojis.
How is Unicode a large character set?
It uses/requires more bits per character than ASCII.
What are character sets?
A collection of characters within the character set and their corresponding binary values.
What does ASCII stand for?
American Standard Code of Information Interchange
What is the key element in images that allow them to be converted to binary?
Pixels.
What is the resolution of an image?
The number of pixels in the image and their dimensions/positioning.
What is the colour depth of an image?
It is the number of bits used to represent each colour.
How do i calculate the size of an image file?
Resolution * colour depth * number of images in the file
What happens as image resolution and colour depth increase?
The file size and quality of the image increase.
How does a computer represent sound?
A sound wave is sampled (recorded at intervals) for sound to be converted to binary.
What is the sample rate?
The number of samples taken in a second.
What is the sample resolution?
The number of bits per sample.
What happens as sample rate and resolution increase?
The accuracy of the recording and file size increase.
How big is a nibble.
4 bits
How big is a byte
8 bits
Tho order of the data conversion table. [9]
Bit
Nibble - 4 bits
Byte - 8 bits
Kibibyte - 1024 bytes
Mebibyte - 1024 kibibytes
Gibibytes -1024 mebibytes
Tebibytes
Pebibytes
Exbibytes
How do i calculate the size of a sound file?
Sample rate * sample resolution * length of soundtrack.
What is the purpose of compression?
To reduce the size of a file
What are the benefits of compression? [3]
-Less storage space required.
-Shorter transmission time
-Less bandwith required
-Quicker to upload and download.
What is the difference between lossy and lossless compression?
Lossy permanently removes data while lossless reduces the file size by altering the data.
How does lossy compression work?
It uses a compression algorithm that finds unnecessary data and permanently removes it from the file.
E.g reducing the resolution, colour depth, sample rate or resolution.
How does lossless compression work?
It reduces the file size without permanently removing data. It uses Run Length Encoding to find and group repeating data together.
