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

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