Computer Science for IGCSE & O level - Data Representation (Section 2)

  • 1
    What does the 'digital' in 'digital audio' or 'digital image' refer to?
    Répondre
    (C)
    The representation of data using discrete values
  • 2
    What is the main advantage of using hexadecimal for representing memory addresses?
    Répondre
    (C)
    It's easier to read and understand than binary.
  • 3
    Which of the following is most likely to reduce file size?
    Répondre
    (D)
    Using lossy compression
  • 4
    Which of the following are benefits of data compression?
    Répondre
    A
    B
  • 5
    What is the decimal equivalent of the binary number 1100?
    Répondre
    (C)
    12
  • 6
    What is the purpose of dithering in the context of digital images?
    Répondre
    (C)
    To simulate a wider range of colors.
  • 7
    What is a common application for RLE in images?
    Répondre
    (B)
    Images with large areas of the same color.
  • 8
    If an image is 1024 pixels wide and has a color depth of 24 bits, what is the memory size per horizontal line?
    Répondre
    (C)
    3072 bytes
  • 9
    What happens during a left logical shift?
    Répondre
    (B)
    Bits are shifted left, and 0s are added on the right.
  • 10
    Which of the following best describes the advantages of using hexadecimal in programming?
    Répondre
    A
    B
  • 11
    Which technique is generally utilized in a ZIP archive?
    Répondre
    (C)
    Lossless compression
  • 12
    What decimal value does the hexadecimal digit 'F' represent?
    Répondre
    (D)
    15
  • 13
    What are some key benefits of using error codes in software development?
    Répondre
    A
    B
    D
  • 14
    In the two's complement representation of a signed 8-bit integer, what is the decimal value of the binary number 11111111?
    Répondre
    (B)
    -1
  • 15
    Which of the following is most closely related to image clarity?
    Répondre
    (B)
    Image Resolution
  • 16
    What is the main purpose of using compression techniques like JPEG or MP3?
    Répondre
    A
    D
  • 17
    What is a key benefit of the hexadecimal system in the context of computer programming?
    Répondre
    (B)
    It provides a more human-readable representation of binary values.
  • 18
    Which of the following can be represented with a hexadecimal number?
    Répondre
    A
    B
    C
  • 19
    Which technique is most suitable for compressing photographs?
    Répondre
    (C)
    Lossy compression (e.g., JPEG)
  • 20
    When converting binary numbers to hexadecimal, which grouping is used to facilitate the conversion?
    Répondre
    (B)
    Groupings of 4 bits.
  • 21
    Which of the following are true about logical and arithmetic bit shifts?
    Répondre
    A
    B
    C
  • 22
    In HTML color codes, how are the red, green, and blue components typically represented?
    Répondre
    (B)
    As two-digit hexadecimal numbers.
  • 23
    How many bits are in a byte?
    Répondre
    (B)
    8
  • 24
    Which file format is associated with lossless compression?
    Répondre
    (C)
    PNG
  • 25
    Which of the following best describes the use of hexadecimal in relation to binary?
    Répondre
    (B)
    Hexadecimal is used to simplify and shorten the representation of binary data.
  • 26
    Which of these options is most often linked with lossy compression?
    Répondre
    (C)
    MP3
  • 27
    What does the abbreviation 'RLE' stand for in the context of data compression?
    Répondre
    (C)
    Run Length Encoding
  • 28
    What is the primary goal when using data compression?
    Répondre
    (C)
    To reduce the file size.
  • 29
    Which number system is the foundation for digital computers?
    Répondre
    (C)
    Binary
  • 30
    What does a higher sampling rate affect in terms of the fidelity of the sound?
    Répondre
    (B)
    Increases the fidelity of the sound.
  • 31
    How does a left bit shift affect a binary number?
    Répondre
    (B)
    Multiplies by 2
  • 32
    If an image has a resolution of 1024 x 768, how many pixels does it contain?
    Répondre
    (C)
    786432
  • 33
    What is the advantage of using hexadecimal notation in the context of data representation?
    Répondre
    (A)
    Offers a more compact way of representing binary values.
  • 34
    In two's complement representation, what is the range of values that can be represented in an 8-bit register?
    Répondre
    (C)
    -128 to 127
  • 35
    What is meant by a 'nibble' in computing?
    Répondre
    (B)
    Half a byte.
  • 36
    Which number system uses base-10?
    Répondre
    (C)
    Decimal
  • 37
    What is the range of values that can be represented by a byte (8 bits) in an unsigned integer representation?
    Répondre
    (B)
    0 to 255
  • 38
    What is the purpose of converting between different number systems (e.g., binary, decimal, hexadecimal)?
    Répondre
    (D)
    To represent data in a way that is suitable for both computers and humans.
  • 39
    In Run-Length Encoding (RLE), what does a 'run' represent?
    Répondre
    (A)
    The number of times a single character is repeated consecutively.
  • 40
    Which technique is most appropriate for compressing a photograph?
    Répondre
    (C)
    JPEG
  • 41
    How many bits make up a nibble?
    Répondre
    (B)
    4
  • 42
    What is the maximum number of values that can be represented using a single byte (8 bits)?
    Répondre
    (C)
    256
  • 43
    In a hexadecimal HTML color code, which parts define the intensity of the red color?
    Répondre
    (A)
    The first two digits.
  • 44
    What is the role of the "base" in a number system?
    Répondre
    (A)
    It determines the number of unique digits used.
  • 45
    What is the binary equivalent of the decimal number 13?
    Répondre
    (B)
    1101
  • 46
    What does a '0' in the most significant bit (MSB) of a two's complement number typically indicate?
    Répondre
    (B)
    A positive number
  • 47
    What does the 'bit depth' in an image indicate?
    Répondre
    (C)
    The number of colors that can be displayed.
  • 48
    What is the primary advantage of using lossless compression?
    Répondre
    (C)
    No loss of original data
  • 49
    What does the term 'bit depth' represent in the context of audio recording?
    Répondre
    (C)
    The number of bits used to represent each audio sample.
  • 50
    What does 'sample rate' refer to in the context of audio?
    Répondre
    (C)
    The number of audio samples captured per second.