Understanding Data Transmission Concepts

What is the main purpose of the header in a data packet?

• To store the actual data being transmitted

• To provide error-checking information

• To contain control information such as source and destination addresses

• To indicate the end of the packet

Answer explanation

The main purpose of the header in a data packet is to contain control information such as source and destination addresses, which is essential for routing the packet correctly through the network.

Which part of a data packet is responsible for error detection?

• Payload

• Header

• Trailer

• Footer

Answer explanation

The trailer of a data packet contains error detection information, such as checksums or cyclic redundancy checks (CRC). This allows the receiving system to verify the integrity of the data received.

In which type of data transmission are bits sent one after another over a single channel?

• Parallel

• Serial

• Simplex

• Full-duplex

Answer explanation

In serial data transmission, bits are sent one after another over a single channel, making it efficient for long distances. This contrasts with parallel transmission, where multiple bits are sent simultaneously.

Which type of data transmission allows data to be sent in both directions, but not simultaneously?

• Simplex

• Half-duplex

• Full-duplex

• Parallel

Answer explanation

Half-duplex transmission allows data to be sent in both directions, but only one direction at a time. This is different from simplex (one-way) and full-duplex (both ways simultaneously). Therefore, the correct answer is half-duplex.

What is the primary difference between serial and parallel transmission?

• Serial transmission is faster than parallel transmission

• Parallel transmission uses multiple channels to send bits simultaneously

• Serial transmission uses multiple channels to send bits simultaneously

• Parallel transmission is more reliable than serial transmission

Answer explanation

The primary difference is that parallel transmission uses multiple channels to send bits simultaneously, allowing for faster data transfer over short distances, while serial transmission sends bits one after another through a single channel.

Which mode of transmission is used when data is sent in only one direction?

• Simplex

• Half-duplex

• Full-duplex

• Serial

Answer explanation

The correct answer is Simplex, as it refers to a mode of transmission where data is sent in only one direction, unlike Half-duplex (which allows two-way communication but not simultaneously) and Full-duplex (which allows simultaneous two-way communication).

In a full-duplex transmission, how is data transmitted?

• Data is sent in one direction only

• Data is sent in both directions, but not at the same time

• Data is sent in both directions simultaneously

• Data is sent using multiple channels

Answer explanation

In full-duplex transmission, data is sent in both directions simultaneously, allowing for continuous communication without waiting for the other side to finish, unlike half-duplex where data flows in one direction at a time.

What is the role of parity checks in data transmission?

• To increase the speed of data transmission

• To ensure data is sent in both directions

• To detect errors in transmitted data

• To compress data before transmission

Answer explanation

Parity checks are used to detect errors in transmitted data by adding an extra bit that indicates whether the number of set bits is odd or even. This helps ensure data integrity during transmission.

Which of the following is a characteristic of parallel transmission?

• Uses a single channel for data transmission

• Transmits multiple bits simultaneously

• Is slower than serial transmission

• Only allows data to be sent in one direction

Answer explanation

Parallel transmission is characterized by transmitting multiple bits simultaneously across multiple channels, making it faster than serial transmission, which sends bits one at a time.

How does a parity bit help in error detection?

• By compressing the data

• By adding an extra bit to make the number of 1s either even or odd

• By increasing the transmission speed

• By encrypting the data

Answer explanation

A parity bit helps in error detection by adding an extra bit to the data, ensuring that the total number of 1s is either even (even parity) or odd (odd parity). This allows the detection of single-bit errors during transmission.