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44 Cards in this Set
- Front
- Back
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What does data need to be represented in? |
Binary |
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What is binary? |
Uses two symbols (0 and 1) to represent data in the computer. |
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What is denary? |
A number system based on 10, using digits 0 to 9 |
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When adding two binary numbers there are only 4 possibilities. What are they? |
> 0+0 = 0 > 0+1 = 1 > 1+0 = 1 > 1+1 = 0 (carry the 1) |
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In binary addition, what would the result of 1+1+carried 1 be? |
1 (carry 1) |
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Overflow |
The result of the calculation is too big to fit into 8 bits. |
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Moving binary digits left or right is know as what? |
Binary shifts |
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Shifting binary digits to the left does what to the value? |
Multiplies by 2 for each place shifted |
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Shifting binary digits to the right does what to the value? |
Divides by 2 for each place shifted |
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Hexadecimal numbers are base what? |
Base 16 |
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How many symbols do you need for hexadecimal to represent the digits? |
16 |
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In Hexadecimal what symbols are used to represent digits 10-15? |
A-F |
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To minimise errors associated with data corruption, what is used? |
Check digit |
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What is a character set? |
The complete set of characters available to a computer. |
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What is a character set? |
The complete set of characters available to a computer. |
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What is a character? |
A symbol on a keyboard to generate code for the computer to convert into a symbol to display. |
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What is ASCII? |
A 7 bit code to represent a set of characters available to a computer. |
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In the original 7 bit ASCII code, how many characters did it represent? |
128 |
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In the extended 8 bit ASCII code, how many characters did it represent? |
256 |
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What is UNI code? |
A character set using code pages for a larger range of language symbols. |
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What are images stored in? |
Pixels |
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What is a pixel? |
Dots that make up an image on the screen. |
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How many bits per pixel do you need to store just two colours? |
1 bit per pixel |
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The number of bits used is known as ______ _____? |
Colour (bit) depth |
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In order to represent more colours you need a greater what? |
Colour depth |
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What is the resolution? |
The number of pixels per unit |
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Since data is stored as a set of binary numbers, what other information needs to be included in the image? |
Colour depth and size |
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The data about the data is called what? |
Metadata |
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What is analogue sound? |
Continuously varying data |
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In order to store as binary value, what happens to sound? |
The sound is sampled at intervals and the binary values recorded. |
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What is the frequency of the sampled intervals called? |
Sample rate |
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What is sample rate expressed in? |
kHz |
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True or False: If sound is sampled more frequently, it will be closer to the original. |
True |
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What is another factor that effects the quality of sound and how do you improve it? |
The accuracy of the data stored ~ More bits for each sample |
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What is bit depth in sound? |
The number of bits used to store each sound sample. |
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What is bit rate in sound? |
The number of samples, stored per second. |
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What is the equation for bit rate? |
Sample rate * bit depth |
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What is compression? |
Reducing the size of a file. |
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What are the two types of compression? |
Lossy and Lossless |
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What is lossy compression? Give two examples: |
Some of the data is removed. JPEG and mp3 |
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True or False: In lossy compression the original file be restored from the data. |
False |
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What Lossless compression? Give two examples: |
Data is reorganised and none is removed. TIFF and FLACK |
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True or False: In lossless compression the original file be restored from the data. |
True |
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Which form of compression has the highest compressor? |
Lossy |
