What is a parity check | A method of error detection, a 0 or 1 is added as a extra bit to make sum of bits odd or even |
If even parity is used in ( 0 1 1 0 1 0 1), which number would you add in front? | 0 |
If an odd parity is used in ( 0 1 1 0 1 0 1), which number would you add in front | 1 |
What is a parity byte | When error is detected, receiver dosent know which bit is transferred correctly, therefore parity byte is used |
What are the limitation of parity check | If an even number of bits have been incorrectly transmitted, then it could not be detected |
What is check digit? | The final digit of the code, calculated using all other digit of the code |
What uses check digit? | Barcodes, product codes, vehicle identification number |
What is a checksum? | Number of bits transmitted added up and transmitted with data |
What is ARQ? | Automatic Repeat Request |
What is the definition of ARQ? | A request that is sent by receiving device to tell sender that there is an error |
What is the definition of transmission of data | Is the sending of data from one device to another. It is important to make sure that data is not altered during transmission |
Examples of short distance transmission | Printing |
Examples of long distance transmission | Long distance call |
What is serial data transmission | Data is send one bit at a time down a single wire |
what is parallel data transmission | Data is send several bits at a time down several wires |
Examples of serial data transmission | Long distance calls |
Examples to parallel data transmission | Sending data to printer |
what is simplex data transmission | Data transmission in one direction only |
Examples of simplex data transmission | Keyboard, microphone, doorbell |
What is half-duplex data transmission | Data transmission in both directions non-simultaneously |
Examples of half duplex | Walkie-talkie |
What is full-duplex Data transmission | Data transmission in both directions simultaneously |
Examples of full duplex data transmission | Phone calls |
3 advantages of serial transmission | Good for long distance, low cost, safer transmission |
1 disadvantages of serial transmission | Slower transmission |
2 Advantages of parallel transmission | Good for short distance, quick transmission |
2 disadvantages of parallel transmission | Greater cost, less safe |
What does USB stand for | Universal Serial Bus |
USB has four wires, what are those for? | Two are for power and earth, two are for data transmission |
3 advantages of USB | Different transmission rates exist, can fit only one way prevents incorrect connection, automatically detects and upload device driver |
2 disadvantages for USB | Low transmission rate, older version are not supported |
What does http stand for | Hypertext transfer protocol |
What is the definition of http | A set of rules which must be followed in transferring data across Internet |
In what occasion will it become https | If a type of security is used like (SSL and encryption) |
HTTPS is faster or slower than HTTP | Slower |
What does HTML stand for | Hypertext mark-up language |
What language is HTML | It is not a programming language, it is a mark-up language |
Where is HTML used | The development of webpages |
Give an example of html | <title> Hello World <title/> |
What is html used for | Representing colours on computer screens |
What is html | The main file of a webpage |
What are three parts of html | Structure, presentation and behaviour |
Two parts and ‘structure’ of html and it’s short form | HTML, headings and paragraphs |
Two parts and ‘presentation’ of html and it’s short form | CSS, font and colour |
Two part and ‘behaviour’ of html and it’s short form | JS, widget and interaction with user |
What is long form of IC | Integrated circuit |
What transmission is USB and IC | Serial and parallel |
Why is IC parallel | It needs high speed data transfer and short distance makes it less risky |
Definition of hacking | Gaining illegal access to a computer system |
What are the 2 effect of hacking | Personal information gained, deletion changing corruption of data |
What are 3 methods of avoiding hacking | Firewalls, strong passwords, anti-hacking software |
Definition of viruses | A program which can replicate itself and delete or corrupt files, or causing computer to malfunction |
What are the 2 effect of viruses | Cause computer to crash, malfunction, unresponsive, can delete and corrupt files |
What are 3 methods to avoid viruses | Anti-virus software, be cautious when opening emails, avoid using software form unknown source |
Definition of spyware | Software that gathers key presses on your keyboard and send it to the originator |
What are the 2 effect of spyware | Personal information known, this software can install other soft read cookies and change web browser |
What are 3 methods of avoiding spyware | Anti-spyware software, be alert of your keyboard, use on-screen keyboard |
Definition of web browser | A software which can display a web page on user’s screen |
Examples of web browsers | Google chrome, safari |
what are the four things that a web browser have | Homepage, history of web pages visited, ability to store website, ability to go backwards and forwards of websites |
How does web browser and HTML link | They translate HTML code from website and display result on screen |
What does IP address stand for | Internet Protocol |
What is the definition of IP address | A 32-bit number which is given to each device on the Internet |
What is the difference between MAC address and IP address | MAC address is a unique number which identifies the device on the Internet. IP address gives the location of the device connected to the Internet |
What does URL stand for | Uniform resource locator |
What is the definition of url | An address to a resource on the Internet |
In the link ‘https://www.youtube.com/watch?V=deD’ what is ‘https://‘ called? | Protocol |
In the link ‘https://www.youtube.com/watch?V=deD’ What is ‘www.youtube.com’ called? | Web server name |
In the link ‘https://www.youtube.com/watch?V=deD’ what is ‘/watch?V=deD’ called? | File name |
How does URL change to a webpage? | Web browser will turn web server name to IP address then HTML code is returned and display as corrected formate on page |
What is cookies? | A packet of data sent by web server to web browser |
How do cookies work? | It generates every time a user visits a website, it tracks user and saves it preferences |
Examples of cookies are? | YouTube, douyin |
Are cookies safe? | They gather Anonymous user profile, they cannot collect personal information however they are subjected to privacy concerns |
what does mac stand for | Media access control |
What is the definition of MAC | A unique hexadecimal number made up of 48-bits which identifies device on Internet |
What is the structure of MAC and describe it | Structure of MAC is (NN:NN:NN:DD:DD:DD:). (NN:NN:NN) are called OUI |
What does OUI stand for | Organisationally unique identifier |
OUI are also? | Vendor numbers (company number) |
What is a UAA? | A unique serial number, set by manufacturer however can be change to LAA |
What is LAA? | locally administered address |
Why change UAA to LAA | To get pass network restrictions, certain software needs all MAC address to be certain format |
What symbol is this? | NOT gate |
What symbol is this? | AND gate |
What symbol is this | OR gate |
What symbol is this | XOR gate |
What symbol is this | NAND gate |
What symbol is this | NOR gate |
What is the Logic notation of NOT gate | X= NOT A |
What is the logic notation of AND gate | X= A AND B |
If 0 is the input in NOT gate what is the output? | 1 |
If 0 and 1 is the input in AND gate what is the output? | 0 |
If 1 and 1 is the input in OR gate what is the output? | 1 |
If 1 and 0 is the input in XOR gate what is the output? | 1 |
If 0 and 0 is the input in XOR gate what is the output? | 0 |
If 1 and 1 is the input in NOR gate what is the output? | 0 |
If 0 and 1 is the input in NAND gate what is the output? | 1 |