Cumputer science
🇬🇧
In English
In English
Practice Known Questions
Stay up to date with your due questions
Complete 5 questions to enable practice
Exams
Exam: Test your skills
Test your skills in exam mode
Learn New Questions
Popular in this course
Learn with flashcards
Manual Mode [BETA]
Select your own question and answer types
Other available modes
Complete the sentence
Listening & SpellingSpelling: Type what you hear
multiple choiceMultiple choice mode
SpeakingAnswer with voice
Speaking & ListeningPractice pronunciation
TypingTyping only mode
Cumputer science - Leaderboard
Cumputer science - Details
Levels:
Questions:
40 questions
🇬🇧 | 🇬🇧 |
What is operating system | Provides both the environment in which applications can be run and a useable interface between human and computer |
What is operating system | Provides both the environment and the |
Why do you need to do a horizontal and vertical parity check at the same time | So you can know where the wrong bits are |
Why is just a horizontal or just a vertical parity check insufficient | You only know there is an error, not where it is |
What is echo check | An error detection method where a copy of the data is sent back immediately, if it's not the same, then the original data is sent again |
What is the disadvantage of echo checks | You cannot tell if the error was sent during the original transmission, or during the sending of the copy |
What are the two most common errors when transmitting data | Packet switching, interferance |
What is a checksum | An algorithm calculates a checksum value from the data sent, the same algorithm is used the the receivers side. if they are the same then there is no error, if they are different, then a request is sent to send the original data again. |
What is check digit | All numbers of the code go through an algorithm to get a check digit, once it goes through the algorithm again and the resulting number divides into 11 without remainders, then the number is valid |
What is the process of finding a check digit | Weighting, multiply, addition, remainder, subtraction |
What happens after the check digit is found | Gets weighting (at the right) then added to the original addition, then that number is divided by 11. If there is no remainder then the number is valid |
What is an error detection code also known as | Cyclic redundancy check |
What happens when acknowledgement isn't sent back to the sender in an Automatic Repeat Query | Timeout occurs, the sender then sends the data again, until either an acknowledgement is sent back, or a preset number of sendings is met |
What happens in ARQ | Automatic Repeat Query. When data is sent, an error detection code is also sent. The receiver then sends back a positive or negative acknowledgement. If negative, the sender sends the data again. |
What is syntax highlighting | Colored text based on the type of code AND automatically highlighting errors in code |
What is error checking | IDE automatically finding errors in a program |
What is IDE | Integrated development environment. Text editor with features to help programmers |
What is pretty printing | Automatic spaces and indentations which make code easier to understand |
What is translator in IDE | Translating high level language to low level language for the computer to understand |
What is run time environment | Software that allows any program to be run on a computer |
11 Features of IDE | Syntax highlighting Error checking Line of code Collapsing line Inputs/outputs Autocompletion/correction Pretty printing Translators Run time environment |
What is fixed program computer | A computer that can only perform one task (eg, calculator) |
What is a stored program computer | A computer that can use many programs |
What is CPU | Central processing unit. performs fetch decode execute cycle |
What is CU | Control unit. reads instruction form memory |
What is ALU | Arithmetic logic unit. Does arithmetic (+-/*). Does logic gates (AND NOT OR etc) and comparisons between values (<>=!=) |
What is PC | Program counter. Holds the memory address of the next instruction. |
What is operating system | Provides both the environment in which applications ca be run and a useable interface between humans and computer. |
What is cache | Memory that is in the CPU itself, it is the fastest to access. stores commonly used instructions and data. Improves Cpu performance. |
What is the purpose of a web browser | Software that allows users to access web pages by interpreting HTML to show what is on the website |
Features of web browser | HOme page Bookmarks/favourites History Navigating forward/backward between past websites Cookies Tabs Hyperlinks |
Benefits of compression | Reduced file size. can fit within file size limits. faster file transfer. less bandwidth needed to transfer files. |
Examples of primary storage | RAM ROM |
Examples of external secondary storage | HDD SDD DVD memory stick, blu ray stick, removable hard drive |
What is primary memory | Directly addressable by the CPU. contains RAM ROM and cache memory |
What is secondary storage | Not directly addressable by the CPU. All non volatile Can be external or internal can be optical, magnetic, or solid state |
Features of ROM | Storing factory settings storing start up routines storing set routines (eg, buttons on a controller for turning left, right, stop) |
What is SSL | Secure socket layer. Makes the website secure by establishing an encrypted link between the server and client computer. It is identified by the "S" at the end of HTTPS |
What is and function | This one |