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