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Computer Science for IGCSE & O level - Data Representation (Section 14)

1
If an image is 1024 pixels wide and 768 pixels high, and the color depth is 16 bits, how many bytes are needed to store this image uncompressed?
Answer
(D)
786432 bits
2
Which statement is generally true about a computer's logical shift operations?
Answer
(B)
They can be used for arithmetic operations.
3
What is the most important aspect when choosing a storage device for photos?
Answer
(B)
The storage capacity.
4
What is the advantage of using hexadecimal notation when representing binary data?
Answer
(A)
Reduces the number of digits needed to represent binary data.
5
What are the two main components that create a Hexadecimal number?
Answer
(B)
0-9 and A-F
6
Which is the hexadecimal representation of decimal 15?
Answer
(A)
F
7
In ASCII, what code represents the uppercase letter 'A'?
Answer
(A)
65
8
If you shift the binary number 11010010 two places to the right, what will be the result?
Answer
(B)
00110100
9
Which method is suggested to convert decimal numbers into binary numbers?
Answer
(B)
Successive division by 2 and noting the remainders.
10
Which of the following are advantages of using hexadecimal numbers over decimal numbers in computer science?
Answer
A
B
C
11
What is the relationship between file size, sampling rate, and bit depth for audio files?
Answer
(B)
Increased sampling rate and bit depth usually lead to larger file sizes.
12
What is the main difference between a bitmap image and a vector image?
Answer
(A)
Bitmap images use pixels; vector images use mathematical equations.
13
What is the binary equivalent of hexadecimal FF?
Answer
(C)
11111111
14
Which technique is used to represent an image with less detail in order to save storage space?
Answer
(B)
Lossy compression
15
What is the primary difference between a left bit shift and a right bit shift operation?
Answer
(A)
Left shift multiplies; right shift divides.
16
What is the primary goal of data compression?
Answer
(C)
To reduce the file size.
17
What is the main advantage of lossy compression for video files?
Answer
(B)
Smaller file sizes and faster streaming.
18
What is the correct method for converting a decimal number to binary?
Answer
(B)
Repeatedly divide by 2 and note the remainders.
19
What happens during a logical left shift?
Answer
(B)
The bits move left, and zeros are added on the right.
20
Which of the following compression methods typically results in the smallest file size for a given image?
Answer
(C)
Lossy compression
21
Which factors are considered when calculating the file size of an image?
Answer
A
B
C
22
What is the binary equivalent of the decimal number 10?
Answer
(A)
1010
23
How is the loudness of sound represented digitally?
Answer
(B)
By the amplitude of the sound wave.
24
What is a key advantage of using Lossless compression?
Answer
(A)
The original quality of the content is maintained.
25
Which of the following factors is most relevant when considering image file size?
Answer
(C)
The image's resolution.
26
What is the purpose of the headings in a typical binary number?
Answer
(B)
To represent the position of each digit and its corresponding weight (power of 2).
27
What does the term 'sampling resolution' refer to when considering the size of an image?
Answer
(B)
The number of bits used to represent each pixel's color.
28
Which of the following is a true statement about binary addition?
Answer
(A)
1 + 1 = 10 (with a carry of 1)
29
How does lossless compression work to achieve file size reduction?
Answer
(B)
By identifying and eliminating redundancy in the data.
30
Which statement is true about the conversion between lowercase and uppercase letters in ASCII?
Answer
(C)
Converting between case requires flipping the fifth bit (from the right).
31
Which color does #800080 represent in HTML?
Answer
(A)
Purple
32
Which of the following is most important when considering the file size of a sound file?
Answer
(C)
The sample rate and sample resolution of the file.
33
What are the benefits of compressing files, particularly images and videos?
Answer
A
C
34
If a pixel is represented using 1 bit, how many colors can it display?
Answer
(B)
2
35
Which file format typically uses Lossless compression?
Answer
(C)
PNG
36
What is a nibble?
Answer
(B)
4 bits
37
What is the main benefit of using Run-Length Encoding (RLE) in image compression?
Answer
(A)
It reduces the file size of images with repeating pixel values.
38
In the two's complement system, what is the result when you invert all the bits of a binary number and add 1?
Answer
(A)
The two's complement of the original number.
39
What is the primary disadvantage of using run-length encoding (RLE)?
Answer
(B)
It is only effective for very simple images.
40
What is the purpose of the sampling rate?
Answer
(B)
To convert an analog signal to a digital signal
41
What is the primary purpose of MAC addresses?
Answer
(B)
To identify devices on a network.
42
Which of the following binary numbers represents the decimal number 10?
Answer
(C)
1010
43
What is the main function of an error code in programming?
Answer
(C)
To provide information about an error.
44
If you want to store a large collection of high-resolution photographs, which type of storage device would be most suitable?
Answer
(B)
A hard drive with a large capacity.
45
What is the correct sequence of steps for converting the binary number 11101011 to hexadecimal?
Answer
(B)
Group into 4-bit segments, and then convert each segment directly to its hex equivalent.
46
What does the term 'bit depth' represent?
Answer
(C)
The number of colors that can be displayed for each pixel.
47
What does the HTML tag represent?
Answer
(A)
Red colored text
48
In the context of digital audio, what does 'bit depth' refer to?
Answer
(B)
The number of bits used to represent each sample's amplitude.
49
What is a byte?
Answer
(C)
A group of 8 bits.
50
Which is a characteristic of lossless compression techniques?
Answer
(C)
They preserve all the original data, enabling perfect reconstruction.