Computer Science for IGCSE & O level - Data Representation (Section 18)
1
What is the meaning of the term 'sampling rate' in sound recording?
Απάντηση
(A)
The number of times the sound is measured per second.
2
If a binary number is shifted three places to the left, what is the equivalent arithmetic operation performed?
Απάντηση
(B)
Multiplying by 8
3
What is the relationship between the sampling rate and the size of a digital audio file?
Απάντηση
(C)
A higher sampling rate generally results in a larger file size.
4
Which of the following are advantages of file compression?
Απάντηση
A
B
5
What is the equivalent decimal value of the hexadecimal number '1A'?
Απάντηση
(C)
32
6
Which of these is a key characteristic of the hexadecimal number system?
Απάντηση
(C)
Uses sixteen symbols.
7
Which options accurately describe the characteristics of lossless compression?
Απάντηση
A
B
D
8
If the bit depth of an image is increased from 8 bits to 16 bits, what is the effect on the file size?
Απάντηση
(B)
The file size is doubled.
9
Which color does the HTML code #008000 represent?
Απάντηση
(B)
Green
10
What is the maximum value represented by a single hexadecimal digit?
Απάντηση
(C)
15
11
In HTML, what is the purpose of the hexadecimal color code?
Απάντηση
(D)
To represent different colors used in the web page.
12
The image of a black and white image consists of 64 squares. If each square requires 1 byte of storage, and RLE is applied. What would be the storage requirement for a full black image?
Απάντηση
(B)
2 bytes
13
Which of the following are advantages of data compression?
Απάντηση
A
B
C
14
What does the term 'unsigned integer' mean in computer science?
Απάντηση
(B)
An integer that can only represent positive numbers.
15
A bit is the basic unit of all computing memory storage terms and is either 1 or 0. The word comes from binary digit. The byte is the smallest unit of memory in a computer. 1 byte is 8 bits. A bit is sometimes called a nibble - half a byte. What is the relationship between byte and bit?
Απάντηση
(C)
1 byte = 8 bits
16
What does the term 'bit' refer to?
Απάντηση
(B)
A binary digit
17
If a bitmap image has a color depth of 8 bits, how many different colors can each pixel represent?
Απάντηση
(D)
256
18
What does a higher sampling rate result in for digital audio?
Απάντηση
(B)
Higher sound quality and a larger file size.
19
In run-length encoding (RLE), what is the purpose of representing consecutive identical data values?
Απάντηση
(C)
To reduce the file size.
20
What are the 2 ways in the image that allow to find a negative binary representation?
Απάντηση
C
D
21
What is the main function of the ASCII control characters?
Απάντηση
(B)
Manage text formatting and communication
22
What is the purpose of using compression algorithms like JPEG for images?
Απάντηση
(B)
To decrease the file size while maintaining a reasonable image quality.
23
What will happen if the binary number 1111 is shifted one place to the left?
Απάντηση
(A)
Multiplied by 2
24
What are the key principles of run-length encoding (RLE)?
