Computer Science (16.2.23)

Question 1

What is Data Transmission?

Answer 1

-> the process of transferring data from one point to another
-method egs:
-Copper Cable, Wireless (Radio Frequency), Infra red and Fibre optic

Question 2

How about the speed of transmission?

Answer 2

The amount of data that can be transmitted at one time is referred to as its BANDWIDTH

Question 3

What is Serial Data Transmission?

Answer 3

-Involves one signal being sent at a time over a single wire
-USB uses serial transmission (Universal SERIAL bus)
-Very high data transfer speeds can be achieved

Question 4

What is Parallel Data Transmission?

Answer 4

-Involves a number of parallel wires that allow signals to be sent simultaneously
-It is best suited for data if it has to be sent over a very small distance
-it is the physical properties of each cable thats affects the arrival time of the data

Question 5

What is Skew?

Answer 5

-It is a disadvantage of parallel transmission
-It is caused by each wire in a pt having different properties
-The greater the distance, the greater the issue that Skew can cause

Question 6

What is Crosstalk?

Answer 6

-Another disadvantage of parallel transmission
-the wires are often very close to eachother and sometimes cause electrical interferences between them
-this can cause errors in the data meaning it will have to be re-sent

Question 7

What is Simplex Transmission?

Answer 7

-Allows data to be sent in only one direction
-eg: sending data from the keyboard to the CPU

Question 8

What is Half-Duplex Transmission?

Answer 8

-Allows data to travel both directions but it cannot occur simultaneously-> data can only travel one way at a time
-eg: Walkie Talkies only allow communication one at a time

Question 9

What is Full Duplex Transmission?

Answer 9

-Allows data to travel in both directions simultaneously, it uses to cables for this
-eg: Internet cables that allow download or upload

Question 10

How do Parity Bits work?

Answer 10

-before data is transmitted, both parties agree to use either odd or even parity
-the parity bit is set by the sending party and checked by the receiver
-if the n. of bits do not match the even of odd system it has an error
-the receiver notifies the sender and the parity check will ask for the data to be re-sent (could be bc of the order of the bits…)

Question 11

What are Parity Blocks?

Answer 11

-Uses the same odd and even system to detect errors in data

Question 12

What is Error Checking?

Answer 12

-Computers need methods to check for data transmission errors caused by an interference
-Parity checks, Check digits, Check Sums, Echo checks, ARQ (automatic repeat requests)

Question 13

What does append() do?

Answer 13

Adds an element at the end of the list

Question 14

What does clear() do?

Answer 14

Removes all the elements from the list

Question 15

What does copy() do?

Answer 15

Returns a copy of the list

Question 16

What does count() do?

Answer 16

Returns the number of elements with the specified value

Question 17

What does extend() do?

Answer 17

Add the elements of a list to the end of the current list

Question 18

What does index() do?

Answer 18

Returns the index of the first element with the specified value

Question 19

What does insert() do?

Answer 19

Adds an element at the specified position

Question 20

What does pop() do?

Answer 20

Removes the element at the specified position

Question 21

What does remove() do?

Answer 21

Removes the item with the specified value

Question 22

What does reverse() do?

Answer 22

Reverses the order of the list