Font size
WorksheetsAQA A Level Computer Science 2
Total questions: 85
Worksheet time: 1hrs 10mins
What are the conditions required for a Vernam cipher to be 100% mathematically secure?
The key is used only once, and then destroyed/
The key is made up of truly random characters/
The key must be made up of fewer characters than the plaintext message.
Different keys must be used to encrypt and decrypt a message.
The letter m has an ascii code of 1101101. As part of a Vernam cipher, the key 0101001 is applied to that letter. What is the resulting ciphertext?
1000100
0111011
1100101
1101001
Which of these are advantages of vector graphics over bitmap graphics?
Can be rescaled without distortion
(Usually) a smaller file size
Ideal for photographic images
Each pixel can be modified individually
The bitmap image of the lemming is 6 pixels by 10 pixels. There are 16 available colours for each pixel. Calculate the file size of the image (not including any metadata) in bytes.
30
120
22.5
60
How many different combinations of bit patterns can be represented using ASCII?
127
128
255
256
The bit pattern 0110001 is sent with an even parity bit in the MSB position.
Which of these is the bit pattern receivedt?
00110001
10110001
01100011
01100010
Data is received that had been sent using majority voting. The received bit pattern is 100 000 011 111.
What bit pattern does the receiving device interpret this as?
0011
1010
0001
1001
10.Complete this sentence: .edu is a ……………………… level domain.
A.Top
B.2nd
C.3rd
11.Complete this sentence: A domain name is ……………………… in structure.
A.Linear
B.Sequential
C.Hierarchical
Internet registrars are important because they hold all records of all existing website names and the details of those domains that are available to purchase.
How many Internet registrars are there in the world?
5
10
15
20
What does DNS stand for?
(a)
To connect a computer to a wired network - you need a 'NIC'. NIC stands for
Network Integration Circuit
Network Integration Card
Node Integration Card
Network Interface Card
At the ends of each bus network, to prevent signals reflecting back down the bus - what device is used?
A terminator
An exterminator
A repeater
An Ethernet jack
Which regular expression matches the FSM?
a?bc(dc)*
a|b(cd)+
a+bc(dc)?
a(b|c)d*c*
Select the strings that are matched by the regular expression:
a(b|c)?d
abcbcbcbcd
acd
ad
acccd
Which of the following is Nyquist's Theorem?
e = mc2
file size = sample res * sample rate
fs > 2fmax
Simplify the boolean expression 😆
!(A and B)
A or B
!A and B
A and !B
What is the difference between a static and dynamic data type?
Dynamic data types are fixed and static can change size
A dynamic data type can change size at run time, whereas static cannot
No difference, the are the same
How many comparisons will a Binary Search make to find the number 23 in the list?
3
4
2
10
How many passes will a Bubble Sort need to make to sort this list (in ascending order)?
1
2
3
4
This is one of ....................... laws
Einstein's
Neptune's
Newton's
De Morgan's
What is the job of the logic circuit above?
Checks is a sensor is activated
Adds two binary numbers together
Subtracts one binary number from another
Adds two binary numbers and produces a sum and carry bit
passes data over the physical network
transport layer
internet layer
link layer
application layer
Responsible for packet switching
TCP
UDP
IP
FTP
The Current State is S0 and Input is 1
What is the OUTPUT and Direction
1, L
1, R
0, L
0, R
What is the Big O Notation of Merge Sort?
O(n)
O (n log n)
O(log n)
O(n2)
Which of these tree traversal methods is used to output the contents of a binary tree in ascending order?
Pre-Order
In-Order
Post-Order
Monastic Orders
Preorder Traversal of the tree
1 4 9 5 2 8 3
1 4 9 5 2 3 8
1 4 9 8 5 2 3
If the sequence of operations - push (1), push (2), pop, push (1), push (2), pop, pop, pop, push (2), pop are performed on a stack, the sequence of popped out values
2,2,1,1,2
2,2,1,2,2
2,1,2,2,1
2,1,2,2,2
Which of the following is not an inherent application of stack?
Implementation of recursion
Evaluation of a postfix expression
Job scheduling
Reverse a string
What is the postfix equivalent for the following infix expression?
(2/4)*(5-6)
2 4 5 6 / - *
2 4 / 5 6 - *
2 4 / * 5 - 6
2 4 / 5 - 6 *
What type of object is enclosed in angle brackets in Backus-Naur form?
Definitive
Terminal
Non-terminal
Special
Why is it that Backus-Naur form is capable of representing some languages that cannot be represented by regular expressions?
Backus-Naur form supports definitions
Backus-Naur form supports Recursion
Backus-Naur form supports Selection
Backus-Naur form supports Loops
Which of the following examples uses valid recursion?
<Number> ::= <Digit> | <Digit><Number>
<Name> ::= <Forename><Surname>
<Age> ::= <Digit>|<Digit><Digit>
<Name> ::= <Name>
For the set "A = {1, 2, 3, 4, 5 }"
which is the correct set comprehension
A = {x | x ∈ ℕ ∧ 6 > x ≥ 1 }
A = | x ∈ ℕ ∧ 5 > x ≥ 1
A = (x | x ∈ ℕ A x ≥ 1 )
A = {x ∈ ℕ ∧ 1 > x ≥ 5 }
What is the "Cardinality" of a set?
number of elements of a finite set
number of elements of an infinite finite set
number of elements of a finite or infinite set
number of elements not in a given set
What are the two types of RFID Tags?
Active and Passive
Aggressive and Passive
Wireless and Wired
Male and Female
Which type of storage uses a laser?
Magnetic
Optical
Solid State
A ferry departs from A(-25, 28). It takes 3 hours to reach its destination B(20, -32), travelling in as straight line with constant velocity. Distances are in km. Find the velocity vector of the ferry.
15i + 20j
15i - 20j
20i + 15j
20i - 15j
The case in which a key other than the desired one is kept at the identified location is called?
Hashing
Collision
Chaining
Open addressing
A hash table of length 10 uses open addressing with hash function h(k)=k mod 10, and linear probing. After inserting 6 values into an empty hash table, the table is as shown above.
Which one of the following choices gives a possible order in which the key values could have been inserted in the table?
46, 42, 34, 52, 23, 33
34, 42, 23, 52, 33, 46
46, 34, 42, 23, 52, 33
42, 46, 33, 23, 34, 52
What type of data structure is an array?
Static and mutable
Dynamic and immutable
Static and immutable
When traversing a binary tree, which diagram is post-order?
Which of these is the correct definition of a pixel?
The smallest addressable element of an image
The smallest part of the screen that can be coloured
A square part of an image
One of the 'lights' on the computer screen
The number of bits a system can send per second is bandwidth.
True
False
The compressed representation of the transmitted bit pattern 0000011100000011 using RLE would be...
0 1 0 1
5 3 6 2
5
5 0 3 1 6 0 2 1
Which protocol do stacks follow?
FIFO
LIFO
What is the value of the postfix expression 6 3 2 4 + – *:
1
14
74
-18
Which of these is a full adder?
What is the purpose of a D-type flip flop?
The add two numbers
To add two bits
To only be able to change a bit whilst the clock is on a falling edge
To only be able to change a bit whilst the clock is on a rising edge
What is sampling rate?
The number of samples taken per second
The number of bits used to represent each pitch of sound
The number of pitches of sound
How long the clip is
Which are examples of lossy files?
JPEG
MP3
ZIP
PNG
GIF
What is sampling resolution?
The number of samples taken per second
The number of bits used to represent each wave sample
The number of pitches of sound
How long the clip is
How many octets is an IPv4 address made up of?
1
2
3
4
What does TCP stand for?
Transfer Control Protocol
Transmission Control Protocol
Transfer Character Protocol
Transmission Character Protocol
Which of the TCP/IP model layers is responsible for breaking down the message into packets?
Network
Application
Transport
Internet
How many bytes are there in a Megabyte?
10
1024
1000240
1000000
Given the following inputs, what would be the output?
A = 1, B = 0, C = 0
0
1
True
01
Which legislation governs the act of hacking?
The Freedom of Information Act
The Data Protection Act
Creative Commons License
The Computer Misuse Act
What does the code above demonstrate?
Nested iteration
Nested selection
Condition-controlled iteration
Count-controlled iteration
Which layer of the TCP/IP stack determines which application layer software on the server should deal with a received request by using port numbers?
Application
Transport
Network
DataLink
Which form of transmission results in the clocks for the receiver and transmitter synchronising for the duration of a transmission?
(a)
Which of the following is not a condition required by the vernam cipher?
The key must be truly random.
The key must be transmitted with the data being encrypted/ rendered into ciphertext
The key must not be reused.
The key must be at least as long as the data to be encrypted/plaintext.
The key must be kept securely
The highest frequency component in a sound that is being sampled is 14,500 Hz. What should the minimum sample rate be?
(a)
Which of the boolean equations above are incorrect? Select more than one.
Equation 1
Equation 2
Equation 3
Equation 4
Equation 5
A band is recording and digitising a song to make available as a download from their website.
The song lasts 3 minutes. The sample resolution is 16 bits and a sample rate of 44 kHz has been used. Calculate the minimum amount of storage space, in megabytes (MB), for the song and leave your answer with a precision of two decimal places.
(a)
What is the name of the logic gate above?
(a)
SSID Stands for?
(a)
The number of signal changes (which may occur) in a given period of time/in a second is known as...
(a)
The range of frequencies that can be transmitted across a network connection is known as...
(a)
(a) communication is most notably evidenced with buses, where multiple bits are sent simultaneously.
Convert 0011 1001 into Hexadecimal.
(a)
Calculate the minimum size of file that could be used to store the bitmap image in the figure above. Express your answer in bytes.
(a)
