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Computer Science for IGCSE & O level - Data Representation (Section 3)

1
What is the decimal value of the binary number 10101?
Answer
(D)
22
2
How many hexadecimal digits are required to represent a byte?
Answer
(B)
2
3
What is the binary equivalent of the decimal number 45?
Answer
(A)
101101
4
How many hexadecimal digits are needed to represent a single byte?
Answer
(B)
2
5
If a sound file has a sample rate of 44.1 kHz and a resolution of 16 bits, how many bytes are needed for one second of stereo sound?
Answer
(D)
352800 bytes
6
What is the decimal equivalent of the binary number 1111?
Answer
(B)
15
7
If a sound recording has a bit depth of 16, what does that signify?
Answer
(B)
Each audio sample is represented using 16 bits.
8
What is the relationship between bit depth and the range of sounds represented in digital audio?
Answer
(B)
Higher bit depth yields a greater range of sounds.
9
Which methods can reduce the image file size?
Answer
B
C
10
What does the term 'color depth' describe in the context of images?
Answer
(B)
The number of colors an image can display.
11
What is the range of representable values in a 16-bit two's complement system?
Answer
(B)
-32768 to 32767
12
What do the letters A-F represent in the hexadecimal number system?
Answer
(C)
Numbers from 10 to 15.
13
What is a common reason for using hexadecimal notation in computer programming?
Answer
A
C
14
If an image has a color depth of 16 bits, how many different colors can each pixel represent?
Answer
(C)
65536
15
Which of the following is the hexadecimal color code for the color yellow?
Answer
(C)
#FFFF00
16
What is the main drawback of lossy compression?
Answer
(B)
Some data is lost during the compression process.
17
What are the key roles of binary numbers in digital systems?
Answer
B
C
18
What is the purpose of the carry bit in binary addition?
Answer
(A)
To indicate an overflow
19
What is the correct representation of '2B' in terms of memory addresses?
Answer
(A)
A valid hexadecimal memory address.
20
When converting between binary and hexadecimal, which groupings are typically used?
Answer
(C)
4 bits to 1 hex digit
21
If a computer's memory address is represented as 2A, what number system is being used?
Answer
(C)
Hexadecimal
22
Which of the following options would result in the largest file size for an image?
Answer
(D)
High resolution, high colour depth
23
What does the hexadecimal digit 'E' represent in terms of its decimal equivalent?
Answer
(D)
15
24
How many different colours can be represented with a 24-bit colour depth?
Answer
(D)
16777216
25
If the hexadecimal value for red color is FF0000, what will it be in binary?
Answer
(A)
111111110000000000000000
26
If an error code is '0x000A', what type of representation is this?
Answer
(C)
Hexadecimal
27
In a digital image, what determines the detail level of the image?
Answer
(C)
Resolution
28
In the context of digital images, what is 'pixels' short for?
Answer
(A)
Picture elements
29
Which of these is the correct representation of the binary number 110011 in hexadecimal?
Answer
(B)
63
30
What is the purpose of Run-Length Encoding (RLE) in image compression?
Answer
(C)
To replace repeated sequences of data with a count and a single value.
31
What effect does increasing the bit depth have on the dynamic range of a sound recording?
Answer
(A)
It increases the dynamic range.
32
What is a key characteristic of lossy compression?
Answer
(B)
It discards some of the original data.
33
What is the decimal value of the binary number 11100?
Answer
(C)
30
34
If a sound file is sampled at 44.1 kHz, what does this sampling rate mean?
Answer
(B)
44,100 samples are taken per second.
35
Which statements correctly describe two's complement representation?
Answer
A
B
C
36
In a two's complement system, how is the number -5 represented in an 8-bit format?
Answer
(C)
11111010
37
Which of the following statements are true about bitwise operations?
Answer
A
B
C
38
What does the term 'bitrate' refer to in the context of digital audio or video?
Answer
(C)
The amount of data used per unit of time (usually per second).
39
In a bitmap image, what does each pixel store information about?
Answer
(A)
The color and brightness of that point in the image.
40
In audio recording, what does 'sample rate' represent?
Answer
(B)
The number of samples taken per second.
41
In converting a binary number to decimal using powers of two, what is the significance of the position of each digit?
Answer
(B)
Each position represents a different power of 2, starting from the right.
42
Which of the following is an application of run-length encoding?
Answer
(B)
Compressing text documents with repeating characters.
43
What are the key benefits of a universal character set like Unicode?
Answer
A
B
44
In which situations is lossless compression often used?
Answer
A
C
45
What would be the value of the color green in hexadecimal form?
Answer
(B)
#00FF00
46
Which number system uses 16 symbols to represent values?
Answer
(C)
Hexadecimal
47
What is the maximum number of colours that can be represented using HTML color codes?
Answer
(B)
16,777,216
48
What is the purpose of an error code in the context of computer programming?
Answer
(A)
To identify and locate errors in the code.
49
In an 8-bit system, if you have the two's complement representation of -5, what is the process to find +5?
Answer
(A)
Invert the bits and add 1.
50
In data compression, what type of information is usually discarded in lossy compression?
Answer
(B)
Redundant or less perceptible information.