Computer Science for IGCSE & O level - Data Representation (Section 13)

1
If a camera takes a picture with a resolution of 1024x1024 pixels and a color depth of 24 bits, how many bytes of memory would the uncompressed image file require?
Răspuns
(C)
3072 KB
2
In Run Length Encoding, what does 'W6B8' represent, assuming 'W' and 'B' are characters?
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(A)
Six whites and eight blacks in sequence.
3
What is the maximum value representable by a 4-bit unsigned integer?
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(C)
15
4
In a two's complement system, the most significant bit (MSB) indicates:
Răspuns
(B)
The sign of the number.
5
What is the primary goal of representing sound digitally?
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(B)
To allow computers to process and store sound.
6
How can image resolution be defined in terms of pixels?
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(A)
The total number of pixels in an image
7
Which compression technique is typically used for images and videos where some loss of data is acceptable?
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(C)
Lossy compression
8
Which of the following is an example of a lossless compression algorithm?
Răspuns
(C)
Run-length encoding (RLE)
9
What is the significance of 64-bit and 32-bit architectures in terms of the number of bits that the CPU can process at once?
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(B)
64-bit processes 64 bits at once; 32-bit processes 32 bits.
10
What does 'lossy compression' mean?
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(B)
Some of the data in the original file is discarded to reduce file size.
11
In the context of memory storage, what does the term 'byte' represent?
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(B)
8 bits
12
What is a significant disadvantage of lossy compression methods?
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(B)
The original data cannot be fully recovered.
13
What do file compression techniques seek to achieve?
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A
C
14
In the context of audio, which of the following has the most effect on the file size?
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(C)
Sampling rate
15
Convert -12 to an 8-bit two's complement binary number.
Răspuns
(A)
11110100
16
What effect does shifting a binary number to the left have on its value?
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(B)
It multiplies the number by 2 for each position shifted.
17
What is the binary value represented by the hexadecimal digit 'C'?
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(C)
1100
18
How many different combinations can a pixel have if represented by 4 bits?
Răspuns
(C)
16
19
In ASCII, what is used to represent numbers, letters, and characters?
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(A)
Binary codes
20
What term is used to describe the number of times an audio signal is measured per second?
Răspuns
(C)
Sampling rate
21
Which of the following compression methods would be BEST for compressing text documents?
Răspuns
(D)
Run-length encoding
22
What is the main characteristic used to describe sound waves?
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(C)
Amplitude
23
In two's complement, what is the range of values that can be represented using 8 bits?
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(B)
-128 to 127
24
Which color will the HTML code #00FF00 represent?
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(B)
Green
25
In the context of HTML, what do the hexadecimal values represent?
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(C)
Color
26
What is the hexadecimal representation of the binary number 1010?
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(A)
A
27
How is the sign of a number indicated in two's complement representation?
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(D)
By the sign bit (most significant bit).
28
What is the binary equivalent of the hexadecimal number 2A?
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(B)
10101010
29
What is the decimal equivalent of the hexadecimal number 'A'?
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(B)
10
30
If an image's resolution is increased, while keeping its color depth constant, what is the effect on the file size?
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(C)
The file size will increase.
31
What does the frequency of a sound wave determine?
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(B)
The pitch of the sound
32
In an 8-bit register, what is the range of numbers that can be represented using the two's complement format?
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(B)
-128 to 127
33
When would you use a lossy compression method?
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A
B
34
If you shift the binary number 11000010 two places to the left, what is the result?
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(D)
11001000
35
Which of the following is NOT a characteristic of sound waves?
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(D)
Color
36
Which statement best describes the relationship between sample rate and audio quality?
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(C)
A higher sample rate potentially results in a higher quality.
37
What is the decimal equivalent of the binary number 1101?
Răspuns
(C)
13
38
In the context of data storage, what is the meaning of 'bit depth'?
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(A)
The number of bits per pixel.
39
Which of the following statements regarding lossless compression is correct?
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(C)
Lossless compression can restore the original data completely.
40
What is the result of adding the two binary numbers: 1101 + 0110 ?
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(B)
10010
41
What is the binary equivalent of the decimal number 7?
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(C)
111
42
In two's complement, to represent the negative of a number, you do the following.
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(B)
Invert the bits and add one.
43
Which statement correctly describes the relationship between a binary number and its equivalent decimal value?
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(B)
Each bit position in a binary number represents a power of 2.
44
What is the function of a MAC address?
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(B)
To uniquely identify devices on a network
45
What is the largest integer that can be represented with 16 bits?
Răspuns
(B)
65535
46
If you are compressing a text file using RLE and encounter the string "AAAAABBBCC", how would the string likely be represented after compression?
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(D)
A5B3C2
47
What does the term 'amplitude' represent in a sound wave?
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(B)
The loudness of the sound.
48
Which compression technique results in the most significant file size reduction?
Răspuns
(C)
Lossy compression
49
If a sound recording has a higher sampling rate, what is its most likely effect on file size and quality?
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(D)
Larger file size, higher quality.
50
How are the remainders used when converting a decimal number into a binary number?
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(B)
They are used to create the binary number by reading them in reverse order.