Computer Science for IGCSE & O level - Data Transmission (Section 12)
1
What are some common causes of data corruption during transmission?
2
What is the main purpose of a 'router' within a computer network?
คำตอบ(B)
To connect different networks and forward data packets.
3
What is the primary function of parity checks?
คำตอบ(B)
To detect errors in data transmission.
4
คำตอบ(B)
Compares two values of data to check data integrity.
5
What is the purpose of check digits?
คำตอบ(B)
To identify typing errors.
6
In asymmetric encryption, which key is used to decrypt a message?
คำตอบ(D)
The recipient's private key.
7
In a data packet, what is the main function of the 'trailer' section?
คำตอบ(B)
To help detect transmission errors.
8
What is the main difference between half-duplex and full-duplex data transmission?
คำตอบ(A)
Half-duplex transmits data in one direction, full-duplex transmits data in two directions simultaneously.
9
In a network, what is a common function of a router?
คำตอบ(C)
To connect multiple networks together.
10
When using even parity, and the data byte is 11010010, what should the parity bit be?
11
What is the primary purpose of using a 'check digit' in data transmission?
คำตอบ(B)
To detect errors that may have occurred.
12
What's a defining feature of symmetric encryption?
คำตอบ(C)
It employs a single key for both encryption and decryption.
13
In an echo check, what is sent back to the sender?
14
Which of the following is the biggest disadvantage of using asymmetric encryption?
คำตอบ(A)
It is very complex and time consuming
15
In data transmission, which of these ensures that the correct data is received?
16
Which transmission mode allows data transfer in only one direction?
17
In symmetric encryption, what is used for both encryption and decryption?
คำตอบ(C)
A single, shared secret key
18
What are the main components of a packet?
คำตอบ(B)
Header, payload, and trailer
19
Which of the following techniques is used for error detection?
20
What is the purpose of using a public key in asymmetric encryption?
21
Which of the following best describes what 'plaintext' means in data security?
22
What is the main goal of encryption?
คำตอบ(C)
To make data unreadable to unauthorized users.
23
What is the term used for the encrypted data?
24
What do you call the original format of a message before it is processed through an encryption algorithm?
25
What is the main function of encryption?
คำตอบ(B)
To prevent unauthorized access to data.
26
When does data corruption most likely occur?
คำตอบ(A)
When the connection is poor
27
In the context of data packets, what does 'payload' mean?
คำตอบ(B)
The data itself that is being transmitted.
28
In packet switching, what information does the 'hop number' represent?
คำตอบ(B)
The number of routers the packet has traversed.
29
What does the sender typically do with the public key in an asymmetric system?
30
Which of the following can lead to data corruption during transmission?
31
What is the main goal of using a digital signature?
คำตอบ(B)
To provide message authenticity and non-repudiation.
32
What type of error can block parity detect?
คำตอบ(C)
Errors where a single bit is changed in any byte.
33
What is a potential vulnerability when using symmetric encryption?
คำตอบ(A)
The key exchange process.
34
What is the core purpose of encryption?
คำตอบ(B)
To make data unreadable to unauthorized parties.
35
Which of the following is a disadvantage of serial data transmission?
คำตอบ(A)
Slower transmission rates over longer distances.
36
What is the main purpose of check digits in data entry?
คำตอบ(B)
To detect typing or scanning errors.
37
Which method is used to reverse the encryption process?
38
Which method of transmission sends data one bit at a time?
39
What type of error can parity checks detect?
40
In a walkie-talkie, what type of data transmission is employed?
41
What is a checksum used for?
42
What is the purpose of a checksum?
คำตอบ(B)
To ensure data integrity during transmission.
43
If even parity is used, and the data being sent is 1101010, what should the parity bit be set to?
44
What does the section on check digits mention they are used for?
คำตอบ(C)
To detect errors from typing or scanning.
45
In the context of data security, what does 'non-repudiation' mean?
คำตอบ(C)
The sender cannot deny having sent a message.
46
If an error is detected during data transmission using ARQ, what happens next?
คำตอบ(C)
The data is retransmitted.
47
Which type of encryption uses a single secret key for both encryption and decryption?
48
What key must be kept secret in symmetric encryption?
49
What key is used to encrypt data in asymmetric encryption?
50
In the context of data transmission, what is 'synchronization' primarily concerned with?
คำตอบ(C)
Ensuring the sender and receiver are coordinated.
