Chapter 1 MS
Eng. Omar Elsafty
Chapter 1 MS
Question
1(a)
1(b)
Answer
•
•
•
One from:
Data that is constantly varying // Continuous data
Non-discrete data // by description
By example, e.g. data such as a sound wave
•
•
One from:
Discrete data that has only two values
By example, e.g. binary data / 1’s and 0’s
Question
Marks
1
1
Answer
Marks
2(a)
•
•
Computer consist of transistors / logic circuits/gates …
… that can only store/process data in two states / high-low / on-off / 1 and 0
2
2(b)
•
•
01000000
11110010
2
2(c)
•
•
0100 (1 mark) 0010 (1 mark)
1100 (1 mark) 1110 (1 mark)
4
1
Chapter 1 MS
Question
Eng. Omar Elsafty
Answer
Marks
3(a)
3
3(b)
2
2
Chapter 1 MS
Question
4(a)
Eng. Omar Elsafty
Answer
One mark for correct binary value, one mark for leading zeros
Marks
2
00000000 01000111
4(b)
One mark for leading zeros, one mark for correct binary value
2
00000001 00000001
4(c)
0516
1
5(a)
2
5(b)
255
1
5(c)
11
1
3
Chapter 1 MS
Eng. Omar Elsafty
Question
6(a)
6(b)
Answer
•
•
A binary number system uses 0 and 1 values
A denary number system uses 0 to 9 values
•
•
A binary number system has units/placeholders/column headings that increase by the power of 2
A denary number system has units/placeholders/column headings that increase by the power of 10
•
Binary has more digit for the same value // Denary has less digits for the same value
•
•
•
7 (a)
4
Any four from:
• A binary number system is a base-2 system
• A denary number system is a base-10 system
Five from:
•
•
•
Marks
5
Correct column headings / place holders by example
Correctly place a 1 or a 0 for each column
Identify the columns to be added
Add together the (denary) values identified..
.. this will give a total which is the denary number/answer
Answer is 10
1 mark for correct method, 1 mark for correct answer
2
32 + 16 + 8 + 1
(00)111001
4
Chapter 1 MS
7(b)
Eng. Omar Elsafty
registers must have leading zeros, allow follow through from 7(a) for an incorrect value
2
1 mark for each correct register
7(c)
Two from:
•
data
•
ASCII value / Unicode value / character
•
number
•
part of image / small image
•
a sound / sound sample / small sound track
•
instruction
2
5
Chapter 1 MS
Question
Eng. Omar Elsafty
Answer
Marks
8
6
9
2
10(a)
Base- 10
1
10(b)
5
4
32
26
171
6
Chapter 1 MS
Eng. Omar Elsafty
Question
11(a)
Answer
One mark for two correct characters, two marks for three, in the correct place
•
Marks
2
0100 0000 0100
11(b)
172
1
12(i)
B
1
12(ii)
C
1
13
6
7
Chapter 1 MS
14
Eng. Omar Elsafty
One mark each:
Movement
4
Binary
Denary
Hexadecimal
forward 1 step
00011111
31
1F
back 1 step
10001100
140
8C
turn right
01011010
90
5A
turn left
01111000
120
78
15
8
Chapter 1 MS
Question
16
Answer
Any three from:
• Error Messages
• Debugging // Memory dump
• ASCII Code // Unicode
• IPv6 address
• MAC Address
• Locations in memory
• Assembly language
• URL
Question
17
18(a)
Eng. Omar Elsafty
Marks
3
Answer
Marks
Any two from:
• Error Messages
• Debugging // Memory dump
• ASCII Code // Unicode
• IPv6 address
• Locations in memory
• Assembly language
• URL
2
Any one from:
• To represent HTML colour codes
• In error messages
•
URL
1
9
Chapter 1 MS
18(b)
19
Eng. Omar Elsafty
Any one from:
• Assembly code/language
• Memory address locations
• In error messages
• Debugging // Memory dump
1
Any three from:
•
Easier/quicker to read/write/understand
•
Easier/quicker to identify errors/debug
•
Takes up less screen/display space
•
Less likely to make mistakes // Fewer errors made in data transcription
•
Easier to remember
3
20
Two from:
• Easier/quicker to read/write/understand
• Uses fewer characters // shorter
• Less likely to make mistakes // less error prone
• Easier/quicker to identify errors/debug
2
21
Any two from:
• It is easier for user to read/recognise/understand
• It takes up less space on a display
• Easier to remember
2
10
Chapter 1 MS
Eng. Omar Elsafty
22 (a)
(b)
23(a)
11
Chapter 1 MS
Eng. Omar Elsafty
(b)
24
Question
Answer
12
Marks
Chapter 1 MS
25
Eng. Omar Elsafty
One mark each:
4
16 bytes = 32 nibbles
512 KiB = 0.5 MiB
4 GiB = 4096 MiB
3 EiB = 3072 PiB
13
Chapter 1 MS
Eng. Omar Elsafty
26
Question
Answer
Marks
27(a)
•
•
(A list of) all the characters and symbols that can be represented by a computer system.
Each character and symbol is assigned a unique value.
2
27(b)
•
Each character is encoded using more bits.
1
14
Chapter 1 MS
Eng. Omar Elsafty
Question
28
29
Answer
Two from:
Marks
2
•
Unicode allows for a greater range of characters and symbols than ASCII (including different languages)
•
Text stored using Unicode takes up more storage space than ASCII //Unicode requires more bits per character
than ASCII
•
Unicode can represent emojis
Pixel
3
The smallest element used to make up an image
Colour depth
The number of bits representing each colour // Size of each pixel in bits
Resolution
The number of pixels wide by the number of pixels high // The number of pixels in an image
30
Sampling resolution
2
The number of bits representing each sample
Sampling rate
The number of samples taken in a second
15
Chapter 1 MS
Eng. Omar Elsafty
Question
Answer
31
Marks
3
Resolution: 150 x 100 = 15000 pixels
File Size in Bytes: 15000 x 16 / 8
= 30000 bytes
32
3
File Size in Bytes: 256 x 200 x 16 / 8 = 1024000 bytes
File Size in KiB: 5x102400 / 1024
= 500 KiB
33
Length of Audio in Seconds: 2 x 60 = 120 seconds & Sampling Resolution in Bytes: 16 / 8 = 2 bytes
3
File Size in KiB: 120 x 2 x 1024 / 1024
= 240 KiB
34
3
Colour Depth in Bytes: 16 / 8 = 2 bytes
File Size in MiB: 2 x 4096 x 2048 /1024 /1024
= 16 MiB
16
Chapter 1 MS
Eng. Omar Elsafty
Question
Answer
Marks
35(a)
2048 MiB
1
35(b)
2 GiB
1
One mark for the correct answer
•
25.6
4
36
Three marks for three stages of working
•
•
•
100 x 100
10 000 x 16 then / 8
20 000 / (500*1024) = 25.6
// 10 000 x 2
37
3
17
Chapter 1 MS
Question
Eng. Omar Elsafty
Answer
Marks
38(a)
3
38(b)
3
39 (a)
2
18
Chapter 1 MS
Eng. Omar Elsafty
Question
39(b)
Answer
-121
Marks
2
99
40(a)
40(b)
2
-91
2
113
19
Chapter 1 MS
Eng. Omar Elsafty
41
20
Chapter 1 MS
Eng. Omar Elsafty
42
1
1
1
21