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Computer Science - Marcador
Computer Science - Detalles
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430 preguntas
| 🇬🇧 | 🇬🇧 |
| 1 kilobyte is how many bytes | 1024^1 bytes |
| 1 megabyte is how many bytes | 1024^2 byte |
| What is 1 bit of data | 0 or 1 |
| What is the sequence for data storage smallest to larger | Bits nibble bytes kilobytes megabytes gigabytes terabyte petabyte |
| What is a overflow error in computing | When a calculation is run but computer can’t store the answer correctly |
| What is a register | A small piece of memory where values can be held |
| What are 3 ways to store characters | Ascii extended ascii and unicode |
| What is the difference between ASCII and Extended ASCII? | ASCII has 7 bits and extended ASCII has 8 bits |
| What is the definition of a character set? | A defined list of characters recognised by the computer |
| What is metadata | Additional data storage with width height colour and depth of image |
| What is the formula of raw file size of an image | (Width*height*colour depth)+10% of metadata |
| What does a compression do | Reduce number of bits in files |
| What is lossy compression suitable for | Images, sound and video |
| What is the definition of lossy compression? | Compressing file where some data of the original file will be lost |
| What is the definition of loseless compression | Compressing file with no data lost but encoded differently |
| What is analogue to digital conversion | Analogue signal transferring to digital binary |
| Low bit depth means | Lower quality |
| Low sample rate means | Lower quality |
| Higher bit depth means | Higher quality 1 |
| High sample rate means | Higher quality |
| What is the definition of sample size | Total number of bits in sound |
| What is the formula for sample of size | Bit depth* number of sample per sec* number of seconds |
| 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 |
| 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 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) |
| 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 |
| 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 |