G11 - CS - End of unit 2 test - Soheil Meskini | Library

Instructions

Answer all the questions.

You may NOT use a calculator.

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

7

3

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

2

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

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: _______ 

8

Data can be encrypted using asymmetric encryption.
Use the terms from the list. Some of the terms in the list will not be used. You may use a term more than once.

algorithm        binary        cipher text          compression          error           hardware 
     hexadecimal           meaningless              plain text             private           public 
   readable               transmission              unreadable


Data is encrypted using an encryption key. This is a type of _______ that scrambles the _______ and turns it into _______. This makes the data _______.
A _______ key is used to encrypt the data. This key cannot be used to decrypt the data. A _______ key is used to decrypt the data. Any device is able to request the _______ key, but only your device knows the_______ key. 

6

Write an algorithm using pseudocode to ask for a password and check that the length of the password is between 8 and 12 characters inclusive.
Your pseudocode should prompt "too short" or "too long" if password entered in outside the above range, and should continue asking until correct password length is entered.

6

State, with reasons, which validation checks you could use for the following inputs.
You may decide that more than one validation check is required.
– Entering a telephone number
– Entering a pupil’s name
– Entering a part number in the form XXX999, when X must be a letter and 9 must be a digit.

Draggable item		Corresponding Item
Data sent 16 bits at a time down 16 wires in both directions simultaneously		Simplex, Serial
Data sent one bit at a time down a single wire 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 one direction only		Full duplex, Parallel
Data sent 8 bits at a time down 8 wires in one direction only		Simplex, Parallel

	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

G11 - CS - End of unit 2 test

G11 - 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:

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.

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.

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.

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.