slr3 computer science

• Lossless compression is used for

  executable program files and documents
• what can lossy compression be used for

  pictures, sound and video
• Why is compression used?

  When a file is compressed, it takes up less disk space than an uncompressed version and can be transferred to other systems more quickly.
• compression will

  reduce the size of a file
• Naturally produced sound is:

  analogue
• The impact of resolution on file size:

  larger file size and greater quality
• The resolution of an image can be expressed in:


  Pixels per inch (ppi)
• The file size can be calculated as:

  Width x height x colour depth
• On a monitor display, pixels are arranged in:

  rows and columns
• The term pixel is short for:

  picture element
• how many numbers are represented on Extended ASCII

  256
• how many numbers are represented on ASCII

  128
• A character set is

  a defined list of characters recognised by the computer.
• How many gibibytes are in a tebibyte?

  1024 gibibytes
• How many mebibytes are in a gibibytes?

  1024 mebibytes
• How many kibibytes are in a mebibyte?

  1024 kibibytes
• how many bytes are in a Kibibyte

  1024 bytes
• how many numbers are in a byte

  8 bits
• how many numbers are in a nibble

  4 bits
• how many numbers are in a bit

  1
• what does logical right shift do


  division
• what does logical left shift do

  multiplication
• what does every one do in twos compliment binary if the number is negative

  takes away
• Two's complement representation can be used to represent both __________ and ________ numbers in binary.

  positive negative
• What is hexadecimals base?

  Base 16
• What is denary's base?

  base 10
• What is Binary's base?

  Base 2
• what is the Maximum number of states possible with 8 bits

  256
• "There are ______ possible states with n bits."

  2n
• Why do computers store data in binary


  it is easier to represent two states using electrical components.