Computer GK
Computer GK - Part2
72) What are different types of Computer Viruses?
| Type of Computer Virus | Details |
|---|---|
| Boot Sector virus | Affects your computer when you start. For example it may come from USB port |
| Web scripting virus | It attacks code of websites or browsers |
| Browser hijacker | Hijacks browser functions |
| Resident virus | Inserts into memory and executes when operating system loads |
| Direct action virus | Acts when you execute a file containing a virus |
| Polymorphic virus | Polymorphic virus |
| Polymorphic virus | Inserts malicious code into executable files |
| Multipartite virus | Infects and spreads in various ways |
| Macro virus | Stored as part of a document and spreads when documents are transferred |
73) What is the virus full form?
Vital information Resource under Siege
74) What are some of the popular computer viruses?
Code Red: It attacked computers running Microsoft IIS web server. It duplicated and destroyed system resources. Launched service attack on several IP addresses including White House.
ILoveYou: It came in email with the subject line “I love you”. It got downloaded when users clicked the attachment Love-Letter-For-You.txt.vbs”. It overwrote system files and spread
Storm Worm: It had an email about oncoming bad weather and attacked computers
Zeus: It is a Trojan horse that infected Windows computers
75) What is Anti-virus software?
It is the computer software that protects against viruses and malware. It prevents the virus from entering the system. If virus already exists, it removes the virus
76) What are the types of Operating System?
| Operating System(O/S) | Details |
|---|---|
| Batch O/S | Similar jobs are grouped together into batches and executed one at a time |
| Time-Sharing O/S | Processor time is shared by multiple users simultaneously. CPU switches between jobs |
| Distributed O/S | Data processing jobs are distributed among processors |
| Network O/S | It runs on a server and allows sharing of resources by multiple computers |
| Realtime O/S | This is time-bound and processing is within constraints |
77) What is a network?
It is connecting together of multiple computers to share information and files between them
78) On what basis are computer networks classified
They are classified on geographical basis
79) What are the types of network?
Local Area Network(LAN): It links computers within a limited geographical area. They are connected by cables
Wide Area Network(WAN): It is a collection of LANs
Metropolitan Area Network(MAN): It is a hybrid between LAN and WAN
80) Network components
| Network Component | Details |
|---|---|
| Hub | It broadcasts the input to all the ports connected to the network. It is in the Physical layer |
| Switch | It sends the traffic to an intended specific device. It is in data link layer |
| Bridge | Previously it used to connect 2 LANs. Recent bridges perform as switches. It is in data link layer |
| Router | It connects multiple devices to internet using the same IP. It is in network layer |
| Gateway | It is required when different technologies are implemented by different LANs that are connected. Example telephone uses ISDN and internet IP. |
| Modem | Converts digital signals of a computer to analog signal |
81) What is network topology?
It is the way in which the computer are connected in a network
82) What are the types of network topologies?
| Network Topology | Details |
|---|---|
| Bus | Multiple devices are connected to a single communication line. Only one device can data at one time. All devices are independent |
| Ring | Each node is connected to 2 other nodes. Messages travel in the same direction. Failure of one node breaks down the whole network |
| Star | All devices are connected to a central device which may be hub, switch or router. If the central device fails whole network fails |
| Mesh | Messages can take several possible paths from source to destination. If eah node is connected to other nodes it is a full mesh |
| Tree | It is a mixture of bus and star topologies. Multiple star networks are connected to a bus |
83) What is a record and a file?
Record is a collection of fixed number of fields. A sequence of bytes is a file
84) What are the different types of file organization?
Sequential: Data can be accessed in the order written
Indexed: It is a file with an index. A record can be accessed randomly with a key
Relative: Records are accessed by their location relative to the beginning of the file
85) What is internet?
It is interconnected computer networks world-wide
86) What protocol internet uses?
It uses TCP/IP.
87) How is a computer in the internet identified?
It is identified by a unique IP address
88) What is an IP address?
It is a set of four numbers separated by period (example is 192.150.212.3). Each number can be between 0 and 255.
89) What are different categories of IP addresses
90) What are private IP addresses?
They are unique identifiers for each device. Each device connected to the internet has a private IP address
91) What are consumer IP addresses?
They are the web browser or payment gateway addresses where payment is done
92) What is a public IP address?
It is the primary IP address associated with the network. It is provided to the router by the internet service provider.
93) What are static IP addresses?
Static IP addresses do not change. Other devices on the internet can find the websites attached to static IP address consistently
94) What are dynamic IP addresses?
They change regularly and automatically. ISPs re-assign IP addresses periodically.
95) What are website IP addresses?
They are Shared IP addresses and Dedicated IP addresses. Websites hosted on shared hosting will have shared IP addresses. A website can be accessed using only the Dedicated IP address instead of domain name
96) What is DNS (Domain Name System)?
It is a naming system for devices or resources connected to the internet or private network. It translates domain names to IP addresss
97) When did internet experiment start?
Internet started in 1960s as an experiment by Advanced Research Projects Agency (ARPA) of U.S. Department of Defence
98) When did the experimental network started by ARPA went online?
In December 1969
99) What is the predecessor of internet?
ARPANET is the first network to use Internet protocol
100) Which are the details of the first message sent over ARPANET?
It was sent by computer science professor Leonard Kleinrock of University of California, Los Angeles to Stanford Research Institute
101) When was the TCP/IP introduced?
In 1982 TCP/IP was introduced on ARPANET
102) What is a search engine?
It is a software that is used to search information on world wide web
103) What is SERP(Search engine results pages)
The search results presented
104) What is web crawling?
It is systematically browsing the World Wide Web for the purpose of web indexing. Search engine uses web crawlers/bots for the purpose
105) What is robots.txt file?
It is file used to tell web crawlers which pages shouldn’t be indexed.
106) What is HTTP(Hyper text transfer protocol)?
Web browsers allows web browsers to communicate with web servers
107) What are the 3 main types of computers by architecture?
Analog computers, Digital computers and Hybrid computers
108) What are analog computers ?
Analog computers operates on mathematical variables in the form of continuous changing entities like mechanical, electrical etc. Examples are speedometer and thermometer
109) What are digital computers?
They use the binary number system. They process the data in discrete. Examples are PCs, Smartphones
110) What are hybrid computers?
Computers that have both analog and digital features
111) What are the types of computers by size?
Super Computer: Powerful, fast and most expensive computers. Used for specific purposes like Weather forecast etc.
Mainframe Computer: Large sized general purpose computer that processes large amount of data at high speed
Mini Computer: These are small computers. Example is Smartphone, iPad etc
Micro Computer: The general purpose computer used for day to day work. Example is Laptop
112) What is cloud computing?
It is on-demand availability of computer system resources without direct active management by the user. It is accessing of computer resources online. It is platform independent.
113) What are the types of Cloud Computing?
| Type of Cloud Computing | Details |
|---|---|
| Public Cloud | Owned and Operated by 3rd party providers. Hardware, Software and other resources are owned by 3rd party and delivered over internet |
| Private Cloud | Large general purpose computer that processes large amounts of data at high speed. Industries use this to process complex data |
| Hybrid Cloud | Mini computers are smaller. Examples are Smartphone, ipad |
| Community Cloud | Resources are shared between organizations |
114) What are the types of Cloud Services
| Type of Cloud Service | Details |
|---|---|
| Infrastructure as a Service(IaaS) | Infrastructure is rented from a cloud service provider on pay-as-you-go basis |
| Platform as a service(Paas) | Provides on-demand environment for development. Custom applications can be developed |
| Software as a service(Saas) | Software applications are delivered over the internet on internet mostly on subscription. Cloud service providers host and manage the software application and infrastructure |
115) Some examples of cloud computing
Google Cloud, Microsoft 365, Microsoft Power BI, Adobe Creative Cloud, Slack and Creatio
116) What are the benefits of Cloud Computing?
It reduces IT costs as infrastructure can be hired for the time and purpose needed, It is reliable, it is platform independent, it is scalable, can access infrastructure and services on internet
117) What is a computer high level language?
It is a programming language that enables to write programs independent of computer. Some examples are Python, Java, C, Fortran, Pascal, PHP etc
118) For what purposes are the high level languages Java, Prolog, Pascal and Fortran used?
Java is a general purpose language, Prolog is used in artificial intelligence, Pascal is used in teaching and Fortran is used in scientific applications
119) What are the low level languages?
Machine level language is in binaries of 1 and 0. It is the lowest level language understood by machine and difficult to understand by humans.
Assembly language communicate directly with hardware. It is readable by humans.
120) What is Computer Hardware?
Hardware consists of physical parts of computer.
121) What is Computer Software?
It is a collection of instructions through which user can communicate with computer and perform tasks
122) Some examples of Computer Hardware?
Motherboard: It is the board with integrated circuit that connects other parts of computer
Central Processing Unit(CPU): It performs most of the functions of a computer.
Keyboard: Input device
Monitor: Output device
123) What are the types of software?
System software interacts directly with hardware. Examples are operating systems, device drivers etc.
Application software is used by users to perform their tasks. Examples are Word Processing, Microsoft Word, Excel, Power point etc.
124) What is OSS?
It is Open Source Software. Anyone can download the software, modify it and redistribute it
125) What is an interpreter?
An interpreter is a translator, which is a computer program that translates the high level language code to machine language
126) What is an Assembler?
Assembler translates the assembly language to machine code
127) What is the difference between a command and a program?
A command does a specific job. A program is a set of instructions
128) What is a process?
A program is a set of instructions and the process is the execution of those instructions. It is executed by one or more threads.
129) How does an user interacts with a computer?
User interacts with either application software or system software which in turn interacts with the operating system which in turn interacts with the hardware
130) Which device is used to transmit data over telecommunication lines?
Modem
131) What is a drive bay?
It is a standard sized area for adding hardware to a computer. They can be fixed or removable. Example USB can be connected to computer using drive bay