Computer Science for IGCSE & O level - Data Representation (Section 4)

  • 1
    Which component of a sound wave is associated with its pitch?
    Răspuns
    (C)
    Frequency
  • 2
    What is the primary aim of using lossy compression?
    Răspuns
    (B)
    Reducing file size.
  • 3
    What is the maximum value of a single hexadecimal digit?
    Răspuns
    (C)
    15
  • 4
    What does the term 'MSB' stand for in computer science?
    Răspuns
    (B)
    Most Significant Bit
  • 5
    What is a common use case for hexadecimal notation in computer graphics?
    Răspuns
    (A)
    Specifying colors.
  • 6
    What best explains how the resolution affects image quality?
    Răspuns
    (D)
    A higher resolution generally leads to a higher quality image.
  • 7
    What is the main advantage of two's complement for representing integers?
    Răspuns
    (B)
    It simplifies arithmetic operations.
  • 8
    What is the result of shifting the binary number 1010 two places to the left?
    Răspuns
    (B)
    1000
  • 9
    Which of the following are true about two's complement?
    Răspuns
    A
    B
    C
  • 10
    What is the key characteristic of a lossy compression algorithm?
    Răspuns
    (B)
    It discards some data to reduce file size.
  • 11
    What does higher bit depth in audio signify?
    Răspuns
    A
    B
  • 12
    What happens when a number is left-shifted in an 8-bit register and the MSB is a 1?
    Răspuns
    (D)
    The value might be incorrect due to overflow.
  • 13
    What is the main advantage of using lossy compression over lossless compression?
    Răspuns
    (B)
    Smaller file sizes
  • 14
    What value is represented by the HTML color code #FFFFFF?
    Răspuns
    (D)
    White
  • 15
    If the two's complement representation of a signed 8-bit integer is 10000000, what is its decimal equivalent?
    Răspuns
    (C)
    -128
  • 16
    How many bits does a byte typically contain?
    Răspuns
    (B)
    8
  • 17
    What is the hexadecimal value for the decimal number 12?
    Răspuns
    (C)
    C
  • 18
    What are the common uses for RLE compression?
    Răspuns
    A
    B
    D
  • 19
    What does the term 'channel' represent in audio recording, particularly in stereo sound?
    Răspuns
    (C)
    A separate stream of audio information (e.g., left or right).
  • 20
    What does the amplitude of a sound wave represent?
    Răspuns
    (C)
    The loudness or intensity of the sound.
  • 21
    What does the sampling rate of a sound refer to?
    Răspuns
    (B)
    The number of times the sound wave is measured per second.
  • 22
    What is the smallest unit of memory in a computer?
    Răspuns
    (B)
    Bit
  • 23
    If you have the hexadecimal value 7F, what is its decimal equivalent?
    Răspuns
    (A)
    127
  • 24
    What is the decimal equivalent of the hexadecimal number 2A?
    Răspuns
    (C)
    40
  • 25
    What are the common uses of Run-Length Encoding (RLE)?
    Răspuns
    A
    B
  • 26
    If a camera takes a photograph, what type of file is produced?
    Răspuns
    (B)
    JPEG
  • 27
    What are the steps involved in converting a decimal number to binary using the method of repeated division?
    Răspuns
    (A)
    Repeatedly divide the decimal number by 2, and the remainders, when read in reverse order, are the binary equivalent.
  • 28
    Which of the following affects the file size of a bitmap image?
    Răspuns
    A
    B
  • 29
    What is the term for the number of bits used to represent each color component (red, green, blue) in a digital image?
    Răspuns
    (B)
    Bit depth
  • 30
    What does the term 'colour depth' refer to in the context of bitmap images?
    Răspuns
    (B)
    The number of colours that each pixel can represent.
  • 31
    Why is hexadecimal commonly used when representing color values, such as in HTML or CSS?
    Răspuns
    (B)
    Because it provides a simple, easily understood representation of color components.
  • 32
    Which compression method is used to reduce the size of data while maintaining its original form?
    Răspuns
    (B)
    Lossless
  • 33
    Which of the following statements are true regarding bit shifting?
    Răspuns
    A
    B
    C
  • 34
    What is a key advantage of using lossy compression algorithms?
    Răspuns
    (C)
    Significantly smaller file sizes.
  • 35
    In hexadecimal, how many binary digits does a single digit represent?
    Răspuns
    (D)
    4
  • 36
    What is the main advantage of using hexadecimal in place of binary?
    Răspuns
    (B)
    Hexadecimal is shorter and easier for humans to read.
  • 37
    When converting binary numbers to hexadecimal values, how many binary digits are represented by each hex digit?
    Răspuns
    (D)
    4
  • 38
    If the binary number 1010 is shifted right by one position, what is the result (assuming a logical right shift)?
    Răspuns
    (C)
    0100
  • 39
    What decimal value corresponds to the hexadecimal digit 'D'?
    Răspuns
    (D)
    13
  • 40
    What is the main characteristic of a lossless compression algorithm?
    Răspuns
    (A)
    It guarantees the complete reconstruction of the original data.
  • 41
    What is the result of the binary addition 1111 + 0001?
    Răspuns
    (A)
    10000
  • 42
    What is the hexadecimal equivalent of the decimal number 15?
    Răspuns
    (C)
    F
  • 43
    What happens when a bit is shifted off the end of an 8-bit register during a left shift operation?
    Răspuns
    (A)
    The bit is lost.
  • 44
    How many different values can be represented with a 4-bit binary number?
    Răspuns
    (C)
    16
  • 45
    Which of the following are advantages of the hexadecimal system?
    Răspuns
    A
    B
    C
  • 46
    Which character set is most commonly used for encoding text in modern computers?
    Răspuns
    (B)
    Unicode
  • 47
    In the context of computers, what does the term 'denary' most closely relate to?
    Răspuns
    (B)
    Decimal numbers
  • 48
    Convert the decimal number 42 to hexadecimal.
    Răspuns
    (A)
    2A
  • 49
    What is the purpose of using run-length encoding (RLE)?
    Răspuns
    (B)
    To compress data by replacing repeated sequences with a shorter representation.
  • 50
    What is the main benefit of data compression?
    Răspuns
    A
    D