Computer Science for IGCSE & O level - Data Transmission (Section 3)
1
What happens if the computer can't find the driver software when a new device is plugged into a USB port?
Απάντηση(A)
The user is prompted to download the appropriate driver software.
2
What is the main characteristic of full-duplex data transmission?
Απάντηση(C)
Data is sent in both directions simultaneously.
3
What kind of key is used for encrypting a document, so that it can only be decrypted by a person who knows the corresponding key?
4
What is the purpose of the 'IP address' in a network?
Απάντηση(A)
To uniquely identify a device on a network.
5
Which of the following is/are features of serial data transmission?
6
What is the main function of the network layer in the OSI model?
7
In which error-detection method is the data sent back to the sender to check for any kind of error?
8
In the context of a USB connection, what happens automatically when a new device is plugged in?
Απάντηση(B)
The USB device is automatically detected, and the appropriate device drivers are installed.
9
What is the main advantage of using a USB connection?
Απάντηση(A)
Faster data transfer speeds.
10
What is the purpose of the packet trailer?
Απάντηση(B)
To identify the end of the packet.
11
What is the main goal of a security protocol?
Απάντηση(C)
Ensure the privacy, authenticity, and integrity of data.
12
Which of the following are methods of error detection?
13
What is the primary method to detect an error during the transmission?
14
What is the role of a 'router' in a home network?
Απάντηση(B)
To connect devices to the internet and manage network traffic.
15
What is a potential drawback of using echo checks?
Απάντηση(C)
They can increase transmission time.
16
What are the key elements in a typical ARQ system?
17
Which protocol is used for transferring files?
18
What best describes the function of an 'Intrusion Detection System (IDS)'?
Απάντηση(B)
To detect malicious activity and log security events.
19
What is the primary function of a "modem"?
Απάντηση(C)
To convert digital signals to analog signals and vice versa.
20
What is the purpose of a "timeout" in the context of automatic repeat request (ARQ)?
Απάντηση(B)
To automatically retransmit data if an acknowledgement isn't received.
21
In a network, what function does a router mainly perform?
Απάντηση(A)
Sends data packets to the correct destination.
22
What does the term 'encryption key' refer to?
Απάντηση(B)
The secret code used to encrypt or decrypt data.
23
In the context of a network, what does the term 'node' usually represent?
Απάντηση(A)
A device that forwards packets.
24
What mode of data transmission permits simultaneous sending and receiving of data?
25
How is the check digit calculated in the ISBN-13 system?
Απάντηση(B)
By using a modulo 10 operation on a weighted sum of the first 12 digits.
26
In the context of data transmission, what does the term 'bandwidth' refer to?
Απάντηση(B)
The amount of data that can be transmitted over a network in a given time.
27
What is the relationship between the public and private keys in asymmetric encryption?
Απάντηση(B)
One is used to encrypt and the other to decrypt.
28
Which component identifies the final destination of each data packet?
Απάντηση(B)
The IP address in the header
29
What does the 'Presentation Layer' do in the OSI Model?
Απάντηση(C)
Formats and encrypts data.
30
What type of data transmission does USB-C support?
31
What does the abbreviation 'TCP' stand for?
Απάντηση(A)
Transmission Control Protocol
32
In which transmission mode can data be sent in one direction only?
33
If data is sent simultaneously in both directions, it's an example of:
34
What is a 'router' mainly responsible for?
Απάντηση(C)
Connecting multiple networks and forwarding data packets between them.
35
What is the primary function of a network 'switch'?
Απάντηση(B)
To intelligently forward data to the destination device only.
36
In the context of data transmission, which of the following best describes the concept of an "Automatic Repeat Request (ARQ)"?
Απάντηση(C)
A method to request the retransmission of data if an error is detected.
37
What is the primary function of the parity bit in data transmission?
Απάντηση(B)
To detect errors in the data.
38
What is the difference between a 'bridge' and a 'router'?
Απάντηση(A)
A bridge connects networks; a router forwards data between networks using IP addresses.
39
What is the primary goal of a 'man-in-the-middle' (MITM) attack?
Απάντηση(B)
To intercept and potentially alter communications between two parties without their knowledge.
40
Which component is used for digital signature in a asymmetric encryption?
41
What is a possible disadvantage of implementing a checksum in data transmission?
Απάντηση(A)
Increased processing overhead for both the sender and the receiver.
42
What does "full-duplex" data transmission enable?
Απάντηση(B)
Data transmission in both directions simultaneously.
43
What does the acronym 'ARQ' stand for?
44
What is the meaning of the acronym 'HTTPS'?
Απάντηση(A)
HyperText Transfer Protocol Secure
45
What distinguishes serial data transmission?
Απάντηση(B)
Bits are sent one after another over a single channel.
46
What is a 'cookie' in the context of web browsing?
Απάντηση(A)
A small text file stored on a user's computer by a website.
47
What is the difference between the "plaintext" and "ciphertext" in encryption?
Απάντηση(A)
Plaintext is the original data, and ciphertext is the encrypted data.
48
What is the function of the 'payload' section within a data packet?
Απάντηση(B)
To contain the actual data being transmitted.
49
In packet switching, what determines the route of the packets?
Απάντηση(B)
The destination IP address
50
How does the hop number of a packet change as it travels through a network?
Απάντηση(C)
It is decremented at each hop.
