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