Computer Science for IGCSE & O level - Data Transmission (Section 10)
1
In parity checking, what is the meaning of 'EVEN' parity?
отговор(A)
The number of 1s in the byte, including the parity bit, is even.
2
What is the main function of a 'checksum' in data transmission?
отговор(B)
To verify the integrity of the data.
3
Which type of data transmission is best suited for transmitting data over long distances?
4
What is the principal function of a 'router' within a computer network?
отговор(B)
To connect different networks and forward data packets between them.
5
What is the fundamental principle behind an echo check?
6
What is the primary purpose of sequence numbers in packetized data transmission?
отговор(B)
To ensure that data packets are reassembled in the correct order.
7
Which of the following is a characteristic of a 'router'?
отговор(B)
It connects different networks.
8
Which type of transmission mode does a typical telephone conversation use?
9
What is the goal of error detection techniques?
отговор(B)
To identify if data was altered or corrupted.
10
What does the term 'backward compatible' mean in the context of USB?
отговор(B)
Older USB devices work with newer USB ports.
11
What is the primary function of the payload in a packet?
отговор(B)
To contain the actual data being transmitted.
12
Which technique is typically used to verify data integrity during transmission?
13
Which type of data transmission allows data to be sent in both directions, but only one direction at a time?
14
Which of the following are common components found in a data packet?
15
What is the result of encrypting data with a key?
16
If a byte has an odd number of 1s and odd parity is used, what should be the value of the parity bit?
17
What is the function of the receiving computer when using a checksum?
отговор(B)
To calculate the checksum value from the data.
18
What is a benefit of using checksums over parity checks for error detection?
отговор(B)
Checksums can detect multiple-bit errors more effectively.
19
Which data transmission method is used to ensure that the data reaches the recipient?
20
Which method is used to ensure the data has arrived correctly?
21
In packet switching, what does the term 'hop number' signify?
отговор(B)
The number of routers a packet has passed through.
22
What does 'ARQ' primarily aim to achieve?
отговор(B)
Reliable data transmission.
23
Which of the following statements best describes the function of a router?
отговор(B)
Forwards data packets between different networks.
24
What can cause data corruption during transmission?
25
What purpose does the IP address serve in a data packet's header?
отговор(B)
To identify the source and destination devices.
26
What does the header of a packet typically include?
27
What is a potential disadvantage of using parity checks?
отговор(B)
They can only detect errors in a single bit.
28
Which type of data transmission is used in a broadband internet connection?
29
What is the primary function of a 'router' in a computer network?
отговор(B)
To connect different networks and direct traffic between them.
30
What best describes the role of a hashing algorithm?
отговор(B)
To create a unique 'fingerprint' of data.
31
In odd parity, how is the parity bit determined?
отговор(C)
The parity bit is set to ensure the total number of 1s, including the parity bit, is odd.
32
Which of the following is a benefit of USB?
33
What does the term 'plaintext' refer to in cryptography?
отговор(C)
The original, unencrypted message.
34
In asymmetric encryption, which key encrypts the data?
отговор(C)
The receiver's public key.
35
In parity checking, what is the purpose of the parity bit?
отговор(C)
To detect errors in the data.
36
What type of error is a checksum designed to detect?
отговор(B)
Errors during transmission
37
What type of data transmission is most suitable for a video conference?
38
What is the function of the 'hop number' in a packet switching network?
отговор(B)
To prevent packets from circulating indefinitely.
39
What is a key difference between symmetric and asymmetric encryption?
отговор(A)
Symmetric uses one key; asymmetric uses two.
40
Which key is needed to decrypt a message that was encrypted with a public key?
41
In half-duplex data transmission, data can be sent...
отговор(C)
In both directions but not at the same time.
42
Which of the following are applications of automatic repeat request(ARQ)? (Select all that apply)
43
Which encryption method uses the same key to encrypt and decrypt data?
44
What is the function of a digital signature?
отговор(B)
To authenticate the sender and ensure the data's integrity.
45
What problem do check digits help to solve?
отговор(C)
Errors from typing or scanning.
46
In symmetric encryption, the security of what component is most crucial?
47
What is the role of a 'key' in the process of encryption?
отговор(B)
To transform the plaintext into ciphertext.
48
What does 'redundancy' in CRC refer to?
отговор(A)
Extra bits added for error detection.
49
Which communication method do you find in a two-way radio?
50
What is the function of the 'sequence number' in a packet header?
отговор(B)
To ensure all packets reach the destination in the correct order.
