G10 - CS - End of unit 2 test - Soheil Meskini | Library

Instructions

Answer all the questions.

2

Explain the term data packet.

3

Data packets contain a header.
Name three components that you would expect to find in a header.

2

Data packets also have a payload and a trailer.
Explain these two terms.

1

What does 'bps' stand for in terms of data transmission?

1

Which transmission allows data to be sent and received at the same time?

4

Using the below diagram, explain how packet switching works when sending a 500 KiB file from computer 'A' to computer 'B'.

6

Match the description of transmission taking place with correct term:

Draggable item		Corresponding Item
Data sent one bit at a time down a single wire in one direction only		Simplex, Serial
Data sent 16 bits at a time down 16 wires in both directions simultaneously		Full duplex, Serial
Data sent 16 bits at a time down 16 wires in both directions, but not at the same time		Half duplex, Serial
Data sent one bit at a time down a single wire in both directions, but not at the same time		Half duplex, Parallel
Data sent one bit at a time down a single wire in both directions simultaneously		Full duplex, Parallel
Data sent 8 bits at a time down 8 wires in one direction only		Simplex, Parallel

7

Indicate which statements about USB are True and which statements are False:

	True	False
USBs use a protocol that allows for error-free data transmission between device and computer
USBs can support any cable length between device and computer
USBs use serial data transfer
USB connections can transfer data using half-duplex or full-duplex
It is difficult to add more USB ports to a computer using USB hubs
USB data transfer rates are much faster than, for example, Ethernet connections
There is no need for devices to have a power source because USB cable supplies 5V of power

3

A system uses even parity.
Indicate whether the following bytes would fail or pass an even parity check:
a)
b)
c)

2

Nine bytes of data were transmitted from one computer to another computer. 
Even parity was used by both systems. An additional byte, called the parity byte was also sent at the end of the transmission.
The following table shows the nine bytes and parity byte following transmission.
One of the bits has been transmitted incorrectly. Indicate which bit is incorrect by
giving its bit number and byte number:
a) bit number: _______ 
b) byte number: _______ 

2

Check digits are used to check data during data entry.
Give two types of error that check digits can identify.

4

ISBN-13 is a type of check digit standard.
The following algorithm generates a check digit for a 12-digit ISBN book code:

1) add all odd-numbered digits together (from left)
2) add all even-numbered digits together and then multiply the result by 3
3) add together the results for steps 1 and 2, and then divide the result by 10
4) take away the remainder of the division from 10, leaving the check digit

Showing your working, calculate the check digit for the following 12-digit ISBN code:
9 781 471 86867

4

An audio CD uses 40,960 samples per second, with 16 bits being used per sample.
The music being sampled uses two channels to allow for stereo recordings.
Calculate the file size for a 1024 second recording. Give your answer in MiB.

3

G10 - CS - End of unit 2 test

Explain the term data packet.

Data packets contain a header. Name three components that you would expect to find in a header.

Data packets also have a payload and a trailer. Explain these two terms.

What does 'bps' stand for in terms of data transmission?

Which transmission allows data to be sent and received at the same time?

Using the below diagram, explain how packet switching works when sending a 500 KiB file from computer 'A' to computer 'B'.

Match the description of transmission taking place with correct term:

Indicate which statements about USB are True and which statements are False:

A system uses even parity. Indicate whether the following bytes would fail or pass an even parity check:a) b)c)

Check digits are used to check data during data entry.Give two types of error that check digits can identify.

An audio CD uses 40,960 samples per second, with 16 bits being used per sample.The music being sampled uses two channels to allow for stereo recordings.Calculate the file size for a 1024 second recording. Give your answer in MiB.

Convert the denary number, −45, into binary, using the two’s complement format.

Data packets contain a header.
Name three components that you would expect to find in a header.

Data packets also have a payload and a trailer.
Explain these two terms.

A system uses even parity.
Indicate whether the following bytes would fail or pass an even parity check:
a)
b)
c)

Check digits are used to check data during data entry.
Give two types of error that check digits can identify.

An audio CD uses 40,960 samples per second, with 16 bits being used per sample.
The music being sampled uses two channels to allow for stereo recordings.
Calculate the file size for a 1024 second recording. Give your answer in MiB.