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

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