Computer Science for IGCSE & O level - Data Transmission (Section 6)
1
Which of these methods require a round-trip of data?
إجابة
B
D
2
What kind of information are used to generate a check digit?
إجابة
B
C
D
3
What is the purpose of a 'proxy server'?
إجابة
(B)
To filter and cache network traffic.
4
Which of the following are examples of network security threats?
إجابة
A
B
C
5
In the context of asymmetric encryption, who is the sender?
إجابة
(A)
The follower
6
What is the function of 'segmentation' in data transmission?
إجابة
(B)
To divide data into smaller, manageable units for transmission.
7
Which is used to identify the errors in data entry?
إجابة
(B)
Check digits
8
How do echo checks identify errors?
إجابة
(A)
By sending the data back to the sender.
9
Which of the following are examples of wired network technologies?
إجابة
A
C
10
What is 'social engineering'?
إجابة
(B)
The practice of manipulating people to gain information.
11
What distinguishes a full-duplex communication mode?
إجابة
(B)
Data is sent in both directions simultaneously.
12
Which of the following is NOT a component of a typical packet header?
إجابة
(C)
The payload.
13
What is the role of a private key in asymmetric encryption?
إجابة
(C)
Decrypt data that was encrypted with the corresponding public key.
14
What are the common causes of data corruption during transmission?
إجابة
A
B
C
15
Which of the following is the biggest disadvantage of using asymmetric encryption?
إجابة
(A)
It is very complex and time-consuming
16
Which of the following is considered a 'layer 1' protocol in the OSI model?
إجابة
(D)
The physical layer
17
What does the term 'firewall' primarily do in terms of network security?
إجابة
(B)
Filters network traffic based on predefined rules.
18
What does full-duplex communication allow?
إجابة
(B)
Data to be sent in both directions simultaneously.
19
What is the purpose of error-checking methods such as checksums and parity bits?
إجابة
A
C
20
How does 'red-time streaming' relate to packet switching?
إجابة
(A)
It increases the likelihood of packets getting reordered.
21
What are the key characteristics of serial data transmission?
إجابة
(A)
Sends bits one at a time over a single channel.
22
What is the role of a sequence number in the packet header?
إجابة
(B)
To reassemble packets in the correct order.
23
What type of data transmission is commonly used for longer distances?
إجابة
(C)
Serial
24
Which type of data transmission is usually preferred for long distances?
إجابة
(B)
Serial data transmission.
25
In the context of ISBN-13 calculation, which operation is used to calculate the check digit?
إجابة
(B)
Modulo
26
What is the main advantage of asymmetric encryption over symmetric encryption?
إجابة
(C)
Higher data security
27
What is an example of "plaintext"?
إجابة
(D)
An email's body before encryption
28
What is the main limitation of using parity checks for error detection?
إجابة
(A)
It can only detect single-bit errors.
29
What is a key advantage of using packet switching in a network?
إجابة
(B)
More efficient use of network resources.
30
Which of the following are types of error detection techniques?
إجابة
A
B
31
What are the benefits of using a USB system?
إجابة
A
B
C
32
What is the function of the 'sequence number' in a packet's header?
إجابة
(C)
To help reassemble packets in the correct order.
33
What is the role of the 'payload' in a data packet?
إجابة
(B)
To contain the actual data being transmitted.
34
How does half-duplex data transmission work?
إجابة
(B)
Data is sent in one direction at a time.
35
Which of the following uses an excluded value which is a result after blocks of data, the receiving computer also calculates the value from the blocks of data and compares the values?
إجابة
(C)
Checksum
36
Which layer of the OSI model is responsible for formatting the data before transmission?
إجابة
(A)
The Presentation Layer
37
What can cause data corruption during transmission?
إجابة
A
C
38
Which type of transmission mode allows for sending data in only one direction?
إجابة
(C)
Simplex
39
In the context of data security, what does "encryption" achieve?
إجابة
(B)
Protects data by converting it into an unreadable format.
40
What is the primary purpose of the OSI model?
إجابة
(B)
To provide a framework for understanding how networks operate.
41
Which of the following scenarios would be most likely to cause an error detectable by a parity check?
إجابة
(A)
A single bit is flipped during transmission.
42
What is 'malware'?
إجابة
(B)
Software designed to damage or disrupt a computer system.
43
What is the primary goal of using error detection methods in data transmission?
إجابة
(C)
To identify and handle transmission errors.
44
What is a primary advantage of asymmetric encryption?
إجابة
(B)
Simplified key exchange.
45
Which mode enables two-way communication at the same time?
إجابة
(C)
Full-duplex
46
Which of the following is true about the security of symmetric encryption?
إجابة
(A)
The key must be kept secret.
47
What type of error detection involves sending data twice and comparing the two instances?
إجابة
(C)
Repetition
48
What are the possible causes of data corruption during data transmission?
إجابة
A
B
C
49
What is the result of the ISBN-13 calculation for the number 978030640615X (where X represents the check digit)?
إجابة
(C)
2
50
What is the role of 'authentication' in data security?
