Computer Science for IGCSE & O level - Data Transmission (Section 5)
1
Which of the following statement(s) is/are true about the Transport Layer?
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A
C
2
Which of the following are used for error detection?
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A
B
3
What kind of error detection is used when data are sent back to the sender?
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(C)
Echo check
4
Which error-detection technique typically involves the retransmission of data?
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(D)
Automatic Repeat Request (ARQ)
5
Which term applies to a situation where two digits swap their positions in the process of data entry?
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(B)
Transposition Error
6
Which of the following would be best suited for a two-way communication?
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(C)
Full-duplex communication
7
In encryption, which of the following terms is used to describe the message before it is encrypted?
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(B)
Plaintext
8
What is the first number in a node, which is calculated from all the numbers in the code, to ensure the errors in data entry?
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(C)
Check digit
9
What does the term 'encryption' mean?
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(A)
The process of converting data into an unreadable format.
10
What is the main security benefit of using a VPN?
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(B)
It protects your internet traffic from eavesdropping and censorship.
11
Which of the following is a type of attack that attempts to make a network resource unavailable to its intended users?
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(C)
Denial-of-service (DoS)
12
In packet switching, what information does the header include to make sure that the packets can be assembled in the correct order?
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(C)
Sequence number.
13
Which of the following is a benefit of using a switch compared to a hub?
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(C)
Switches forward traffic only to the intended recipient, increasing efficiency.
14
In packet switching, what are the advantages of using different routes?
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B
C
15
Why are packets sometimes reordered when using packet switching?
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(A)
Because each packet may take a different route.
16
What is the function of 'ARP' (Address Resolution Protocol)?
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(B)
To resolve IP addresses to MAC addresses.
17
What is the main security risk associated with using symmetric encryption?
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(A)
The same key is used for both encrypting and decrypting, which can make it difficult to share the key securely.
18
What are some of the main advantages of a wireless network (Wi-Fi)?
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A
B
19
Which of the following is NOT a characteristic of full-duplex data transmission?
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(C)
A single channel is used for transmission.
20
Which of the following statements is true regarding symmetric encryption?
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(C)
It uses the same key for encryption and decryption.
21
Which of the following factors influence how data is transmitted?
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A
B
C
22
In a network, what task does a router primarily perform?
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(B)
Forwarding data packets.
23
Which of the following best describes the operation of an echo check?
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(B)
The receiver sends a copy of the data back to the sender to verify it.
24
What is 'social engineering'?
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(C)
The practice of manipulating people into revealing confidential information.
25
What kind of error could be detected by parity blocks?
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(D)
Both single and burst errors and errors where one bit has changed
26
Which of the following is a function of the 'application layer' of the OSI model?
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(C)
Providing network services to applications.
27
Which of the following best describes "automatic repeat request (ARQ)"?
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(B)
A system for detecting and correcting errors by retransmitting data.
28
In the context of data transmission, what does the term "checksum" refer to?
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(B)
A method of error detection.
29
What does the acronym ARQ stand for?
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(B)
Automatic Repeat Request
30
What are the common methods for detecting errors in data transmission?
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A
B
C
31
What is a 'MAC address' used for?
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(A)
To identify a device on a network at the data link layer.
32
What does USB stand for?
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(A)
Universal Serial Bus
33
What is the key difference between serial and parallel data transmission?
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(A)
Serial transmits data one bit at a time, while parallel transmits several bits simultaneously.
34
When using asymmetric encryption, how is the sender's private key typically used?
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(C)
To create a digital signature.
35
Which of the following are examples of network protocols?
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A
B
C
D
36
What does 'VPN' stand for?
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(A)
Virtual Private Network
37
What is 'spoofing' in a network context?
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(B)
An attack where an attacker impersonates a legitimate entity.
38
What is the purpose of a public key in asymmetric encryption?
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(B)
To encrypt messages only.
39
What is the primary function of the "header" in a data packet?
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(B)
Provides information about the data, such as source and destination addresses.
40
What type of transmission is often used for connecting a computer to a printer via a USB connection?
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(C)
Full-duplex
41
In the example of ISBN-13 algorithm where 978030640615X, what is the calculation algorithm is used?
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(A)
Weighted sum and then divide by 10 to find remainder
42
Why are check digits used?
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(C)
To detect errors, such as when data is entered incorrectly.
43
What is the primary benefit of breaking data into packets before transmission?
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(C)
It allows data to be sent via a different route.
44
Which of the following protocols is often used to encrypt web traffic?
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(C)
HTTPS
45
What is the term for the combination of hardware and software that translates signals from a computer into signals that can be transmitted over a phone line?
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(C)
Modem
46
Which of the following is the correct name for a form of encryption that involves both the sender and the recipient use the same key to encrypt and decrypt?
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(A)
Symmetric key encryption
47
Which of the following is an example of a "checksum"?
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(B)
A hash value used to verify data integrity
48
What is the function of a 'checksum' in data transmission?
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(B)
To detect errors in the data.
49
In asymmetric encryption, what happens if someone has your public key?
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(B)
They can encrypt messages to you.
50
Which method is most suitable for long-distance communication?
