Chapter 1 Information representation Flashcards
What is a bit and what is its value?
One bit is the smallest unit of a computer memory and the value is 1 or 0.
What is a byte?
One byte is a group of eight bits.
How many bytes has one kilobyte?
1024 bytes.
One megabyte how many kylobytes?
1024 kylobytes.
One gigabyte how many megabytes?
1024 megabytes.
What is the difference between denary and decimal number? What are the digits of this system.
Denary and decimal are synonims.
0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
What are the digits of hexadecimal numbering system?
0 to 9, A to F
How do you transform a denary number to a hexadecimal number for example 20?
20:16 = 1
20-16 = 4
4:1=4
Hexadecimal value = 0014
What is the file extension of bitmap?
The file extension for bitmap is .bmp
What is the file extension of a vector graphics image?
The file extension of a vector graphics image is .svg
What is color depth?
Color depth is the number of colors that can be used in an image.
How are pictures stored?
A picture is stored pixel by pixel(position and color): The colors can be stored: - 24 bit color - 16 million colors - Monochrome ( one bit) - 16 color (4 bit) - 256 color (8 bit color)
Audio formats.
WAV -high quality - very large
MP3 - Smaller suitable for websites
MIDI - The smallest and saves the recording like a piece of sheet music. It needs a music synthesizer.
What does bit rate mean?
Bit rate means the number of bits used to store one second of sound or video.
What does the bit rate depend on?
It depends on:
- sample rate (number of times the sound changes per second)
- number of channels (mono, stereo, quad etc.)
- bit depth (range of sound frequencies used or the range of different notes in a music.).
How to determine bit rate(storage)?
sample rate x number of channels x bit depth = bit rate (storage)
What is the difference between lossless and lossy comprassion.
In lossless compression the size of the file gets reduced like in lossy but, it doesn’t lose data quality.
What could happen when sound is compressed?
The music might use fewer channels, have lower sample rate or to have reduced bit depth.
How much is 1111 as an unsigned integer?
2^4-1=15
4 is the number of ones
What is an unsigned integer?
An unsigned integer is a value that can’t be negative.
What are signed integers?
Signed integers are values that can be negative
How are signed integers usually stored?
Signed integers are usually stored using two’s complement or one’s complement.
How does one’s complement work?
Switch the 0 -> 1 and 1 -> 0
How to do two’s complement?
Do one’s complement first and then add 1
Or
Start from the least significant bit and leave all the 0s and the first 1 unchanged. Then, switch all the remaining bits.
