Computer Science for IGCSE & O level - Data Transmission (Section 14)
1
Which is the benefit of Checksum?
პასუხი
(A)
It ensures data has not been altered.
2
Which type of data transmission mode is suitable for a phone call?
პასუხი
(C)
Full-duplex
3
What does the ARQ protocol primarily aim to achieve?
პასუხი
(B)
Error correction.
4
What components make up a packet?
პასუხი
(B)
Header, Payload, and Trailer
5
What is the function of the IP address located in the header of a data packet?
პასუხი
(B)
To specify the sender and receiver of the data.
6
What does the 'payload' section of a data packet contain?
პასუხი
(B)
The actual data that is being transmitted.
7
Which type of encryption uses a single key for both encryption and decryption?
პასუხი
(B)
Symmetric encryption
8
Which of the following is a potential cause of data corruption?
პასუხი
A
C
9
What type of error detection is primarily used for data integrity during transmission?
პასუხი
(A)
Parity checks
10
In asymmetric encryption, which key is used to encrypt the data?
პასუხი
(B)
Public key
11
In a public key system, which key is kept secret?
პასუხი
(B)
Private Key
12
Which of the following is a key goal of cryptography?
პასუხი
(B)
To protect information from unauthorized access.
13
In asymmetric encryption, which key should be kept secret?
პასუხი
(B)
The private key.
14
Which security service can ensure that the sender can't deny that they sent a particular message?
პასუხი
(C)
Non-repudiation
15
In packet-switched data transmission, why are sequence numbers used?
პასუხი
(B)
To ensure that the packets arrive at the destination in the correct order.
16
What is an echo check used for?
პასუხი
(B)
To verify data accuracy.
17
In serial data transmission, the data bits are sent:
პასუხი
(B)
One after another over a single channel.
18
What is a primary goal of cryptography?
პასუხი
(C)
To protect information from unauthorized access.
19
What is the main objective of using parity checks in data transmission?
პასუხი
(B)
To detect errors.
20
In the context of data communication, what is an 'echo check' primarily used for?
პასუხი
(B)
Error detection
21
What is the main distinction between symmetric and asymmetric encryption?
პასუხი
(C)
Symmetric encryption uses one key, while asymmetric encryption uses two keys.
22
What is the main objective when using the parity check method?
პასუხი
(B)
To detect errors in the data
23
What is the unreadable format of data after encryption?
პასუხი
(B)
Ciphertext
24
What is the purpose of a public key?
პასუხი
(B)
To encrypt data.
25
In symmetric encryption, what is the primary requirement for maintaining data security?
პასუხი
(B)
Keeping the secret key protected.
26
What type of data transmission does a walkie-talkie use?
პასუხი
(B)
Half-duplex
27
What type of acknowledgement is sent when the data has an error?
პასუხი
(B)
Negative acknowledgement (NAK)
28
What is a key advantage of using serial data transmission over parallel transmission, particularly concerning the cabling?
პასუხი
(B)
Uses fewer wires, simplifying cabling and reducing cost
29
What security aspect does non-repudiation address?
პასუხი
(B)
Authenticity of the sender.
30
In the context of asymmetric encryption, what is the purpose of the private key?
პასუხი
(C)
To decrypt the data.
31
In the context of data transmission, what does the abbreviation 'CRC' stand for?
პასუხი
(A)
Cyclic Redundancy Check
32
What is the primary difference between symmetric and asymmetric encryption?
პასუხი
(A)
Symmetric uses one key, asymmetric uses two keys.
33
Which of the following methods are used to determine errors in the transmitted data? (Select all that apply)
პასუხი
A
B
C
34
In which data transmission mode can data be sent and received simultaneously?
პასუხი
(C)
Full-duplex
35
What is the main role of a 'router' in a network?
პასუხი
(B)
To connect different networks and forward data packets.
36
What are common causes of data corruption during transmission?
პასუხი
A
B
37
What information is typically included in the 'header' of a data packet?
პასუხი
A
C
D
38
Which of the following statements is most accurate regarding the use of ARQ?
პასუხი
(C)
ARQ is a mechanism for ensuring data reliability.
39
What is the primary role of the 'trailer' section in a data packet?
პასუხი
(B)
To detect and handle transmission errors.
40
What does the term 'trailer' refer to in data packet terminology?
პასუხი
(B)
The end of the packet, used for error detection and control.
41
Which type of key is kept secret in symmetric encryption?
პასუხი
(C)
A shared secret key
42
What does a timeout mechanism in ARQ primarily address?
პასუხი
(B)
Lost or delayed packets.
43
What are the typical components of a data packet?
პასუხი
A
B
C
44
What are the three factors that need to be considered when transmitting data?
პასუხი
(A)
Direction of transmission, method of transmission, and data synchronization
45
Which of the following describes the blocks where the receiving computer sends back a copy of the future the sending computer to allow it to compare the data?
პასუხი
(B)
automatic repeat request
46
What does a negative acknowledgment (NAK) indicate in the ARQ protocol?
პასუხი
(B)
Data has been corrupted during transmission.
47
What is the purpose of a timeout in an ARQ protocol?
პასუხი
(C)
To retransmit data if an acknowledgement is not received.
48
Which method is used if the receiving computer requests the data to be re-sent?
პასუხი
(B)
Automatic repeat request
49
What is the purpose of a 'checksum' in data transmission?
პასუხი
(B)
To detect errors during the transmission of data.
50
What is the purpose of the IP address in the packet header?
პასუხი
(B)
To identify the source and destination of the data.
