Information Technology Class 11

Teachers and Examiners (CBSESkillEduction) collaborated to create the Networking and Internet Class 11 MCQ. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

Networking and Internet Class 11 MCQ

1. In the year __________, all the military communications started using telephone networks setting up dedicated connections between the two parties.
a. 1950s 
b. 1955s
c. 1960s
d. 1965s

2. The US Department of Defense realized the need to connect geographically separated research computers together to form a network. This led to the development of ___________.
a. Internet
b. Arpanet 
c. NSFNet
d. None of the above

3. ARPANET Stands for ___________.
a. Apart Research Project Network
b. Advanced Research Proper Network
c. Advanced Research Projects Agency Network 
d. None of the above

4. Several smaller networks interconnected with each other and create ______ in 1984.
a. Internet
b. Arpanet
c. NSFNet 
d. None of the above

5. NSFNET Stands for _____________.
a. National Science Foundation Network 
b. National Social Foundation Network
c. New Social Foundation Network
d. None of the above

6. TCP/IP network develop in the year of _________.
a. 1965s
b. 1970s 
c. 1975s
d. 1980s

7. Maximum data transfer rate of a network is known as __________.
a. Channel
b. Sender
c. Receiver
d. Bandwidth 

8. __________ is the communication medium through which message is transmitted.
a. Channel 
b. Sender
c. Receiver
d. Bandwidth

9. Information can be transferred only in one direction. This mode is termed unidirectional. In computer networks is known as _________.
a. Simplex Mode 
b. Half-duplex
c. Full-duplex
d. None of the above

10. __________ mode is a bidirectional communication between the two nodes, however, only one node at a time can transmit the data.
a. Simplex Mode
b. Half-duplex 
c. Full-duplex
d. None of the above

11. __________ mode data can be send by both communicating parties and receive at the same time.
a. Simplex Mode
b. Half-duplex
c. Full-duplex 
d. None of the above

12. NIC Stands for __________.
a. Network Interface Card 
b. Network Interchange Card
c. Network Interface Change
d. None of the above

13. A ____________ refers to the channel of transmission through which data can be transmitted from one node to another in the form of signal.
a. Transfer Medium
b. Transmission medium 
c. Bandwidth
d. None of the above

14. Example of the guided medium is ___________.
a. Coaxial cable
b. Twisted Pair cable
c. Optical Fiber cable
d. All of the above 

15. Example of unguided medium is ___________.
a. Microwave
b. Radio wave
c. Infrared
d. All of the above 

16. __________ helps to increase the signal when it become weak and distorted.
a. Repeater 
b. Router
c. Hub
d. Switch

17. ________ is just like repeater which connects two cables or several lines.
a. Switch
b. Hub 
c. Repeater
d. Router

18. _________ helps to connecting two or more local are networks (LAN).
a. Switch
b. Repeater
c. Bridge 
d. Router

19. _________ are used to connect individual nodes in the network with each other. Each node within network is connected to a unique port.
a. Switch 
b. Repeater
c. Bridge
d. Router

20. A _______ maintains a routing table of various networks. Based on the destination address, this device determines to which network the incoming packet should be transmitted.
a. Switch
b. Repeater
c. Bridge
d. Router 

21. A _________ connects networks based on different protocol technologies to communicate with each other.
a. Switch
b. Repeater
c. Bridge
d. Gateway 

22. PAN Stands for _________.
a. Potable Area Network
b. Personal Area Network 
c. PAN Area Network
d. None of the above

23. LAN Stands for _________.
a. Local Area Network 
b. Long Area Network
c. Local And Network
d. None of the above

24. MAN Stands for __________.
a. Main Area Network
b. Metro Area Network
c. Metropolitan Area Network 
d. None of the above

25. WAN Stands for ___________.
a. World Area Network
b. Wide Area Network 
c. Widest Area Network
d. None of the above

26. The arrangement (also called layout) of nodes in a network is called ________.
a. Router
b. Topology 
c. Broadcast
d. Point

28. Example of Broadcast topologies.
a. Bus Topologies
b. Ring Topologies
c. Both a) and b) 
d. None of the above

29. Example of Point to Point topologies.
a. Star Topologies
b. Mesh Topologies
c. Both a) and b) 
d. None of the above

30. In __________, there is a long cable, called backbone cable (or simply backbone), that connects various nodes through a connector called tap.
a. Bus Topologies 
b. Ring Topologies
c. Star Topologies
d. Mesh Topologies

31. In __________, all the devices are attached through a cable in the form of ring.
a. Bus Topologies
b. Ring Topologies 
c. Star Topologies
d. Mesh Topologies

32. In __________, all the devices are connected to the central controller called hub.
a. Bus Topologies
b. Ring Topologies
c. Star Topologies 
d. Mesh Topologies

33. ________ is a hybrid topology using a combination of star and bus topology.
a. Bus Topologies
b. Ring Topologies
c. Tree Topologies 
d. Mesh Topologies

34. Each device on a network has a unique identity known as a ___________.
a. MCA Address 
b. IP Address
c. MAN Address
d. None of the above

35. MAC addresses are _________ hexadecimal (or 48 bit) numbers.
a. 12 digit 
b. 16 digit
c. 32 digit
d. 64 digit

36. Every machine in a network has another unique identifying number, called ________.
a. MCA Address
b. IP Address 
c. Digit Address
d. All of the above

37. Give the example of generic domain name ________.
a. .com
b. .edu
c. .gov
d. All of the above 

38. __________ is the process of getting the corresponding IP address from domain name.
a. Domain Name Resolution 
b. IP Address
c. MAC Address
d. None of the above

39. Digital literacy refers to raising knowledge and awareness about technology such as _________.
a. Desktop Computer
b. Smartphones
c. Tablets
d. All of the above 

40. WWW Stands for __________.
a. World Wide Web 
b. World Web Wide
c. Web Wide World
d. Wide Web World

41. Give a example of email protocols _________.
a. SMTP
b. POP3
c. Both a) and b) 
d. None of the above

42. SMTP Stands for __________.
a. Simple Mail Transfer Protocol 
b. Single Mail Transfer Protocol
c. Some Mail Transfer Protocol
d. Such Mail Transfer Protocol

43. POP Stands for _________.
a. Past Office Protocol
b. Post Open Protocol
c. Post Office Protocol 
d. None of the above

44. FTP Stands for __________.
a. File Translate Protocol
b. File Transfer Protocol 
c. First file Transfer Protocol
d. None of the above

45. TELNET helps to _________.
a. Computer login
b. Remote login 
c. Application login
d. All of the above

46. TELNET Stands for _________.
a. Terminal Network 
b. Team Network
c. Technology Network
d. Test Network

47. ________ is a client server based application that allows the user working on one system to access a remote system.
a. Bridge
b. TELNET 
c. Router
d. Gateway

48. The Internet protocol suite is a set of communications protocols used in the Internet and computer networks. It is commonly known as __________.
a. POP3
b. HTTPS
c. TCP/IP 
d. SMPT

49. Give the example of TCP/IP model.
a. Application Layer
b. Transport Layer
c. Internet Layer
d. All of the above 

50. Data/message is created at the sender’s end and at the receiving end it is examined and processed. This layer is also responsible for enveloping the message to be sent with the header.
a. Application Layer 
b. Transport Layer
c. Internet Layer
d. All of the above

51. Application layer passes the message to the __________ which appends the information about the source and destination ports of the processes at two ends.
a. Application Layer
b. Transport Layer 
c. Internet Layer
d. All of the above

52. Transport layer hands over the segments to the Internet layer which adds source and destination machine network address (also termed IP address).
a. Application Layer
b. Transport Layer
c. Internet Layer 
d. All of the above

53. ________ is also called Host to Internet layer. This layer is responsible for adding the header containing the sender and receiver physical address to the packet received from the Internet layer.
a. Application Layer
b. Transport Layer
c. Link Layer 
d. All of the above

54. A malware may be a __________.
a. Virus
b. Worm
c. Trojan horse
d. All of the above 

55. A _________ is a software code that may harm your system by overwriting or corrupting the system files.
a. Virus 
b. Worm
c. Trojan horse
d. All of the above

56. A _______ is often received via network, and it automatically keeps on creating several copies of itself on the hard disk thereby flooding the hard disk.
a. Virus
b. Worm 
c. Trojan horse
d. All of the above

57. A _________ Virus is a form of malware that installs itself on a computer by impersonating a trustworthy application.
a. Virus
b. Worm
c. Trojan horse 
d. All of the above

58. ___________ is the act of secretly or stealthily listening to the private conversation or communications of others without their consent.
a. Denial of Service
b. Eavesdropping 
c. Phishing
d. Cyber Crime

59. __________ cyber-attack in which the machine or network resource becomes unavailable to its users by temporarily or indefinitely disrupting services.
a. Denial of Service 
b. Eavesdropping
c. Phishing
d. Cyber Crime

60. ___________ refers to the act of stealing a user’s personal information through fraud mails.
a. Denial of Service
b. Eavesdropping
c. Phishing 
d. Cyber Crime

61. Cybercrimes are the crimes related to the misuse of computers or the Internet such as ________.
a. Theft
b. Fraud
c. Forgery
d. All of the above 

62. The ________ defines cybercrime as an unlawful act where in the computer is either a tool or a target or both.
a. IT act 
b. Cybercrime
c. Phishing
d. None of the above

63. ___________ inflicted through the use of electronic or communication devices such as computer, mobile phone, laptop, etc.
a. Harassment
b. Bullying
c. Both a) and b) 
d. None of the above

64. To seek personal information like Customer ID, Net Banking password, ATM PIN, OTP, Card expiry date, CVV etc. through a phone call.
a. Harassment
b. Bullying
c. Vishing 
d. None of the above

65. Dishonestly making use of the electronic signature, password or any other unique identification feature of any other person.
a. Identity theft 
b. Bullying
c. Vishing
d. None of the above

66. Persuading a recipient to buy a product or service, or visit a website via email, SMS, MMS where he can make purchases.
a. Identity theft
b. Spamming 
c. Vishing
d. None of the above

67. The victim is asked to pay the demanded ransom to get his device decrypts.
a. Identity theft
b. Ransomware 
c. Vishing
d. None of the above

68. TCP/IP protocols may be secured with cryptographic methods and security protocol like ________.
a. Secure Socket Layer (SSL) 
b. Firewalls
c. Threads
d. None of the above

69. A _________ aims at protecting the internal network of an organization, home, or individual from malicious traffic from external networks.
a. Secure Socket Layer (SSL)
b. Firewalls 
c. Threads
d. None of the above

70. __________ is software that aims to protect your system against malicious and potentially unwanted programs.
a. Secure Socket Layer (SSL)
b. Firewalls
c. Threads
d. Antivirus 

71. A __________ is a software application that helps a user store and organize passwords.
a. Password cracker
b. Password manager  
c. Password hider
d. None of the above

72. _________ are the laws for systematic use of e-resources, for example, e-business, and serve as a measure against illegal cyber-crime.
a. Cyber crime
b. Cyber laws 
c. Cyber digits
d. None of the above

73. Cyber police are responsible for detecting such crimes and taking the necessary measure against it according to the ________.
a. Cyber act
b. Computer act
c. IT act 
d. None of the above

74. What are the different protective measures while accessing internet.
a. Never click on a suspicious link
b. Make sure that passwords are strong and are change frequently.
c. Never disclose personal information
d. All of the above 

75. Which protocol is best for surfing on the web.
a. HTTPS 
b. HTTP
c. Both a) and b)
d. None of the above

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Computer Organization Class 11 MCQ. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

Computer Organization Class 11 MCQ

1. Computer is an electronic device and works on electronic signals. In computer systems on and off signals denote ________ respectively.
a. 1 and 0 
b. 2 and 9
c. 3 and 8
4. 4 and 6

2. Computers understand only ___________ language.
a. Human Language
b. Binary Language 
c. English Language
d. None of the above

3. _________ helps to convert high level languages to binary languages.
a. Translator 
b. Reader
c. Converter
d. None of the above

4. The data and/or instructions given by the user to the machine are termed as Input and the result
generated by the machine after processing the data is the __________.
a. Process
b. Output 
c. Input
d. None of the above

Computer Organization Class 11 MCQ

5. Advantage/Characteristics of a computer system.
a. Diligence
b. Versatility
c. Accuracy
d. All of the above 

6. IPO Cycle stands for ___________.
a. Input Process Output
b. Individual Person Outcome
c. Internal Process Outcome
d. None of the above

7. The _________ unit holds the data and instructions during the processing.
a. Input
b. Output
c. Memory 
d. None of the above

8.What are the different types of computer storage devices __________.
a. Primary Memory
b. Secondary Memory
c. Both a) and b) 
d. None of the above

9. ___________ memory is directly accessed by the CPU and it is also fast and expensive memory.
a. Primary Memory 
b. Secondary Memory
c. External Memory
d. None of the above

Computer Organization Class 11 MCQ

10. Give some examples of primary memory _________.
a. RAM
b. ROM
c. Both a) and b) 
d. None of the above

11. RAM Stands for _______________.
a. Roman Access Memory
b. Random Access Memory 
c. Randomly Accessible Memory
d. None of the above

12. RAM is also known as ____________.
a. Volatile memory 
b. Non – Volatile memory
c. External memory
d. None of the above

13. Type of RAM ___________.
a. DRAM
b. SRAM
c. Both a) and b) 
d. None of the above

14. DRAM stands for _____________.
a. Dynamic Random Access Memory 
b. Digital Random Access Memory
c. Dynamic Random Accessible Memory
d. None of the above

Computer Organization Class 11 MCQ

15. SRAM Stands for ___________.
a. Sub Random Access Memory
b. Static Random Access Memory 
c. Social Random Access Memory
d. Static Random Accessible Memory

16. ROM is also known as __________.
a. Volatile memory
b. Non – Volatile memory 
c. External memory
d. None of the above

17. PROM Stands for ___________.
a. Programmable Read Only Memory 
b. Program Read Only Memory
c. Prolog Read Only Memory
d. None of the above

18. EPROM Stands for ___________.
a. Electrically Erasable Programmable Read Only Memory 
b. Electrically Erasable Program Read Only Memory
c. Electrically Erasable Prolog Read Only Memory
d. None of the above

19. Give an example of the device which belongs to Secondary Storage ___________.
a. Hard Disk
b. Compact Disk
c. Magnetic Tapes
d. All of the above 

Computer Organization Class 11 MCQ

20. __________ is a chip-based computer component that makes retrieving data from the computer’s memory more efficient.
a. Random Access Memory
b. Read Only Memory
c. Cache Memory 
d. None of the above

21. ___________ coordinates with the peripheral devices to accept the input or display the output. It is like a manager of all operations.
a. Control Unit 
b. Arithmetic Logic Unit
c. Memory Unit
d. None of the above

22. ____________ retrieves the data from the storage unit and performs the arithmetic calculations and/or comparisons on them and the processed data is then sent back to the storage.
a. Control Unit
b. Arithmetic Logic Unit 
c. Memory Unit
d. None of the above

23. __________ is the main circuit board which holds together various components like CPU, memory, connectors for the hard drive and optical drives.
a. Hard Disk
b. MotherBoard 
c. CPU
d. None of the above

24. __________ it is a large printer-like device that is used to take print of large maps, architectural designs.
a. Plotter 
b. Inkjet Printer
c. Laser Printer
d. All of the above

Computer Organization Class 11 MCQ

25. ____________it is an output device that gives an enlarged view of the output on a large screen. It is generally used for giving a view of output to a large audience.
a. LED Monitor
b. Projector 
c. LCD Monitor
d. All of the above

26. Give some examples of processor __________.
a. Dual – core
b. Quad – core
c. Octa – core
d. All of the above 

27. Give some of the examples of processor manufacturing companies ___________.
a. Intel
b. AMD
c. Both a) and b) 
d. None of the above

28. Speed of processors is usually measured in ____________.
a. Megahertz (MHz)
b. Gigahertz (GHz)
c. Both a) and b) 
d. None of the above

29. All the data stored in the c drive of a computer is basically stored in ____________.
a. Hard disk 
b. CD-ROM
c. Pen Drive
d. All of the above

Computer Organization Class 11 MCQ

30. 1 nibble = __________.
a. 4 bits 
b. 8 bits
c. 16 bits
d. All of the above

31. 1024 MB = __________.
a. 1 GB 
b. 1 TB
c. 1 PB
d. 1 Exabyte

32. Digital Video Disc(DVD) are examples of optical storage devices. Capacity of a DVD is higher than ___________.
a. Hard Disk
b. Compact Disk 
c. External Hard Disk
d. All of the above

33. Give some examples of Operating Systems ____________.
a. MS-Dos
b. Solaris
c. Windows 10
d. All of the above 

34. Operating System as an Interface Functions of an Operating system can be broadly categorized as___________.
a. Communication Manager
b. Resource Management
c. Process Management
d. All of the above 

Computer Organization Class 11 MCQ

35. ____________communicating with the peripheral devices or the internet, are addressed by the operating system.
a. Communication Manager 
b. Resource Management
c. Process Management
d. All of the above

36. _________ management helps to process the program currently executing in the memory or waiting for the CPU.
a. Communication Manager
b. Resource Management
c. Process Management 
d. All of the above

37. ____________ component of an operating system allocates memory to the processes in a dynamic manner that is allocated on demand and released when not needed.
a. Communication Manager
b. Resource Management
c. Memory Management 
d. File Management

38. __________ takes care of all the files and folders (directories) maintained on the computer disk. The basic tasks that a user needs to perform on files are creation, renaming, deletion, copying or moving of a file or folder.
a. Communication Manager
b. Resource Management
c. Memory Management
d. File Management 

39. What are the different types of Operating System ____________.
a. Single – tasking and Multi – tasking Operating System
b. Single user and Multi user Operating System
c. Real Time Operating System
d. All of the above 

Computer Organization Class 11 MCQ

40. __________ operating systems allow execution of only a single program at a time.
a. Single tasking Operating System 
b. Multi tasking Operating System
c. Real time Operating System
d. Batch Processing System

41. _____________ operating system can execute more than one program simultaneously. The processor time, in this case, is divided amongst various processes.
a. Single tasking Operating System
b. Multi tasking Operating System 
c. Real time Operating System
d. Batch Processing System

42. ___________ operating systems allow only one user to use the system. The desktop systems can be classified as typical single user systems
a. Single User Operating System 
b. Multi User Operating System
c. Real time Operating System
d. Batch Processing System

43. ____________ operating systems allow many users to access the system by maintaining an account of all the registered users.
a. Single User Operating System
b. Multi User Operating System 
c. Real time Operating System
d. Batch Processing System

44. Operating systems which ensure that the response time is fixed are categorized as ______________.
a. Single User Operating System
b. Multi User Operating System
c. Real time Operating System 
d. Batch Processing System

Computer Organization Class 11 MCQ

45. In a ________________, similar jobs are clubbed together and submitted as a block to the processor for execution.
a. Single User Operating System
b. Multi User Operating System
c. Real time Operating System
d. Batch Processing System 

46. If any computer hardware is not working then ___________.
a. You have to check the cable 
b. Replace the hardware device
c. Destroy the hardware device
d. All of the above

47. To improve the performance of a computer you need to _____________.
a. Shutdown the computer
b. Close running programs that are not being used 
c. Delete all files and folder from the computer
d. None of the above

48. What is a shortcut key for opening a Help window on a computer.
a. F5
b. F4
c. F3
d. F2 

49. Troubleshoot the hardware problem, if the monitor is not showing any display or Screen is blank.
a. Check the System is in Sleep mode
b. Check the Monitor cable
c. If Laptop, check the battery is low
d. All of the above 

50. If the keyboard is not responding then what we have to do.
a. Check the cable connection
b. Check for any damage
c. If wireless keyboard, check the batteries
d. All of the above 

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the RDBMS Class 11 Notes. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

RDBMS Class 11 Notes

Database Management System (DBMS)

A database management system, often known as a DBMS, is required to develop and maintain databases on computers. Users can develop and administer databases using software called a database management system. MySQL, PostgreSQL, Microsoft Access, Oracle, Microsoft SQL Server, DB2, and Sybase are some of the well-known DBMSs.

DBMS allow us to:
· store data in a structured way.
· query the database (that is, ask questions about the data)
· sort and manipulate the data in the database
· validate the data entered and check for inconsistencies
· produce flexible reports, both on screen and on paper, that make it easy to comprehend theninformation stored in the database.

RDBMS Class 11 Notes

Relational Database

The term “relational database” refers to a database that contains data in several tables that are connected by a common column is known as Relational Database.

a. Redundancy can be controlled
b. Inconsistence can be avoided
c. Data can be shared
d. Security restrictions can be applied.

RDBMS Terminology

Domain

It is pool of values or the collection (set) of possible values from which the value for a column is derived.

Tables or Relation in a Database

Relational Databases store data or information in tables. A table is similar to a spreadsheet where data is stored in rows and columns. We can interlink or we can make the relation between the table using a common field.

1. Record – A record in a database is a collection of fields within a table that are relevant to one particular entity. This record is also called row or tuple.
2. Field – The term field is also refer as a column. Each column has a unique name and the content within it must be of the same type. Field is also known as Column and Attribute. 
3. MySQL – It is an Open Source RDBMS Software. It is available free of cost.
4. Key – A key is an attribute or group of attributes that aids in uniquely identifying a row (or tuple) in a table (or relation). When we want to create connections between the various columns and tables in a relational database, we also employ a key.

RDBMS Class 11 Notes

Types of Keys in DBMS

There is a 7 different types of keys, but in your syllabus only 4 keys are given we are going to discusses based on these four key only. 

1. Primary Key – The group of one or more columns used to uniquely identify each row of a relation is called its Primary Key.
2. Candidate Key – A column or a group of columns which can be used as the primary key of a relation is called a Candidate key because it is one of the candidates available to be the primary key of the relation.
3. Alternate Key – A candidate key of a table which is not selected as the primary key is called its Alternate Key. 
4. Foreign Key –  A primary key of a base table when used in some other table is called as Foriegn Key. 

Characteristics of MySQL-

a. It requires no cost or payment for its usage.
b. MySQL has superior speed, is easy to use and is reliable.
c. MySQL uses a standard form of the well-known ANSI-SQL standards.
d. MySQL is a platform independent application which works on many operating systems like Windows, UNIX, LINUX etc. and has compatibility with many languages including JAVA , C++, PHP, PERL, etc.
e. MySQL is an easy to install RDBMS and is capable of handling large data sets.

RDBMS Class 11 Notes

Categories of SQL Commands

SQL commands can be classified into the following categories:

1. . Data Definition Language (DDL)
2. Data Manipulation Language (DML)

Data Definition Language (DDL)

The DDL part of SQL permits database tables to be created or deleted. It also defines indices (keys), specifies links between tables, and imposes constraints on tables.
Examples of DDL commands in SQL are:

• CREATE DATABASE – creates a new database
• CREATE TABLE – creates a new table
• ALTER TABLE – modifies a table

• DROP TABLE – deletes a table

Data Manipulation Language (DML)

The query and update commands form the DML part of SQL: Examples of DDL commands are:

• SELECT – extracts data from a table
• UPDATE – updates data in a table
• DELETE – deletes data from a table
• INSERT INTO – inserts new data into a table

MySQL Data Types

Data types can be broadly classified into following categories:-

1. Numeric Types
2. Alphanumeric Types
3. Date Time

Numeric Types

They are used for describing numeric values like mobile number, age, etc.

• Decimal – Decimal Data type  represent decimal number and store the decimal values in database. 
• Integer – Integer Data type is used for storing integer values.

Alphanumeric Types

Alphanumeric data types are used to store character values in the database like student name, address etc.

• Char(size) – A fixed-length string from 1 to 255 characters in length right-padded with spaces to the specified length when stored. Values must be enclosed in single quotes or double quotes
• Varchar(size) – A variable-length string from 1 to 255 characters in length; i.e. VARCHAR(25). Values must be enclosed in single quotes or double quotes.

Date Time Types

When specifying date and time values for a column used in a database table, date time data types are utilised. Information like a person’s date of birth, admission date, and so on might be stored on it.

• Date (Stores month, day and year information)
• Time (Store hour , minute and second information)

RDBMS Class 11 Notes

Adding constraints in table

Keeping a manual check on the data entering the tables is frequently not possible. The entered info might not be accurate. Constraints, which MySQL offers, are a set of guidelines that assist us somewhat ensure the accuracy of the data. These limitations are:

1. Primary Key – Sets a column or a group of columns as a primary key of the table. Therefore, NULLs and Duplicate values in this column are not accepted. 
2. NOT NULL – Makes sure that NULLs are not accepted in the specified column.
3. FOREIGN KEY – Data will be accepted in this column, if the same data value exists in a column in another related table. This other related table name and column name are specified while creating the foreign key constraint.
4. UNIQUE – Make sure that duplicate values in the specified column are not accepted.

SQL Commands

1. Creating a Database

Syntax – CREATE DATABASE <table name>;

Example – CREATE DATABASE School;

2. Use Database

A database called School is established on the system once the above statement has been executed. You can choose any database name to work on the database.

Syntax – USE <table name>;

Example – USE School;

3. Display the current database

We must know which database we are currently working in, to see the name of the current database we use SELECT command.
Syntax – SELECT DATABASE();

4. Creating a Table

After creating a database, the next step is creation of tables in the database. For this CREATE
TABLE statement is used.

Syntax – CREATE TABLE table_name( column1 datatype, column2 datatype, column3 datatype, ….. columnN datatype);

Example – CREATE TABLE Students(Rollno Integer, Name Varchar(25));

RDBMS Class 11 Notes

5. Create a Table with constraints

Example – CREATE TABLE Shoes (Code CHAR(4) PRIMARY KEY, Name VARCHAR(20), type VARCHAR(10), size INT(2), cost DECIMAL(6,2), margin DECIMAL(4,2), Qty INT(4));

6. Viewing the tables in the database

To see a list of tables present in the current database we will use SHOW TABLES.
Syntax – SHOW TABLES;
Example – SHOW TABLES;

7. Viewing the structure of the table

The DESCRIBE statement can be used to see the structure of a table as indicated in the Create Statement. It displays the Column names, their data types, whether Column must contain data, whether the Column is a Primary key.

Syntax: DESCRIBE <table name>;

OR

DESC <table name>;

Example – DESCRIBE Student;

RDBMS Class 11 Notes

8. Modifying the structure of table

When we create a table we define its structure. We can also change its structure i.e. dd, remove or change its column(s) using the ALTER TABLE statement. ALTER TABLE is used to add a constraint, to remove a constraint, to remove a column from a table, to modify a table column.

Syntax – ALTER TABLE <table name> ADD/DROP <column name> [datatype];

ALTER TABLE <table> MODIFY <column> <new definition> ;

If we want to add a column named Games in the student table .

Example – ALTER TABLE Student ADD Games VARCHAR(20);

9. Deleting the structure of the table

Sometimes there is a requirement to remove a table from the database. In such cases we don’t want merely to delete the data from the table, but we want to delete the table itself. DROP TABLE command is used for this purpose. 

Syntax – DROP TABLE <table name> ;

10. Insert Command

After creating database and relations, we can add data in the relations. INSERT INTO command
is used to enter values in a table. Syntax of insert command is as follows :

Syntax – INSERT INTO <TABLENAME >(COLUMN NAMES>) VALUES (value1, value2, value3,……)

Example – INSERT INTO STUDENT(RNO,GENDER, LNAME,FNAME) VALUES(8,’F’,’SHANU’, ‘DEEPAKSHI’);

11. Select Command

SELECT command is used to view the data from a relation in a database. It returns a result set of data/ records from one or more relations.

Syntax – SELECT <column name> FROM <table name>;

12. DISTINCT ( Displaying values without repetition)

If a column contains repeated values then the select statement gives the result set with repeated values like if a command is given to display DISTINCT keyword is used to eliminate repeated values
Consider the query:
Example –  select marks from student;

RDBMS Class 11 Notes

13. WHERE Clause

Where clause is used to fetch data based on a criteria/ condition. Criteria can be given using an expression.

Syntax:
SELECT <column name1> [,<column name> ,….] FROM <table name>
WHERE <condition>;

Operators 

Arithmetic Operators

• +
• –
• *
• /
• %

Relational Operators

• =
• <
• >
• <=
• >=
• != or <>

Logical Operator

• AND
• OR
• NOT

HANDLING NULL Values

IS operator is used to match NULL value in the expression.
For example, following command is to display the records with NULL values in column edesig from table employee
Example – select empname, zone from employee where zone IS NULL;

IS operator

IS operator is used to compare equality with NULL whereas IS NOT may be used for comparing the values not equal to NULL;
Example – select empname, zone from employee where zone IS NOT NULL;

RDBMS Class 11 Notes

Alias Name to columns

To make the output more user friendly we can give customized heading to column name in the select command. Keyword AS is used to give column alias in a set of single quotes as shown in the example below:
For example :
Example – select rno AS ‘Roll Number’ , fname AS ‘First Name’ , marks from Student;

Inserting Text within the Query SQL

To make the output more user friendly SQL supports inserting text within the output display. The text is displayed only in the output and no changes are made in the table.
For example :
Example – select fname ,’has roll number ‘, Rno AS ‘Roll Number’ from student;

IN operator

IN operator is very useful when we wish to fetch selected records which match a certain set of values. Suppose we wish to display list of students who have score marks 88,90,92,95 , then IN operator can be used as follows :
Example – select fname, marks from student WHERE marks IN (88, 92, 95);

LIKE keyword

LIKE is used for pattern matching and is very useful. Following characters used for applying pattern matching:
%    –     percent symbol is used to match none or more characters
_     –      underscore character is used to match occurrence of one character in the string

For example : To search for records having first name starting with letter ‘R’;
Example – select * from student where fname like ‘A%’;

RDBMS Class 11 Notes

ORDER BY

The result set fetched by the query can be displayed in sorted order. The sorting can be on the basis of any particular column from the table using ORDER BY clause.

Syntax is :
SELECT <column name>, [<column name >…]
FROM <table name>
[ WHERE <condition> ]
ORDER BY < column name> [DESC];

UPDATE

UPDATE command is used to modify data of records within the table. It is a type of DML and is used to make changes in the values entered in the table :
Syntax: `
UPDATE <table name>
SET <column name> = <value>, [<column name> = <value> , …] [WHERE <condition> ];

DELETE

DELETE Command is used to remove records from the table.
Syntax of the command is :
DELETE from <table name> [Where <condition>];

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Office Automation Tools Class 11 Notes. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

Office Automation Tools Class 11 Notes

Digital Documentation OpenOffice Writer

The generation of text-based documents requires the use of word processing software. The user can edit, format, and print documents using its features. Tables and images can both be included in a word document. It could be a book, a letter, an artwork, a website, etc.

Start OpenOffice Writer

To start using the OpenOffice Writer software, any one of the following steps needs to be performed –
Start >> Programs >> OpenOffice

OpenOffice Components

It consists of different components like Tabs, Ruler bar, Status bar, Scroll bar and Work Area. The Writer layout and its general features are described as follows:
a. Tabs – (File, Edit, View, Insert, etc.) contain drop down menu which have commands provided by the tab.

b. RulerBar – There are two rulers – Horizontal and Vertical. The Ruler Bar allows us to adjust the indentation and margins.

c. Status Bar – It displays information about the current open document. It displays the current page number, total pages in the document, zoom slider etc.

d. Scroll Bar – There are two scroll bars – horizontal and vertical. They help to scroll the content or the body of document.

e. Work area – It is the working area where the text of the document is typed.

Writer Tabs

The File, Edit, View, Insert, Format, Tools, Modify, and Window tabs are available in the OpenOffice Writer. A help tab is also included. A drop-down menu with several commands and settings shows when one of the tabs is clicked. Decide which command you want to run.

The key tasks that can be performed using the tabs are as follows

a. File – To apply commands to current document, to open or close document
b. Edit – For editing the current document, for example, cut, paste
c. View – For controlling display of document on the screen
d. Insert – For inserting new elements in document, like, comments, special characters, graphics, and objects
e. Format – For formatting the layout and content of document
f. Tools – For spelling check, gallery of object art to add to document, to configure menus
g. Table – To insert, edit, delete a table in a text document
h. Windows – For manipulating and displaying document windows

File Tab

The OpenOffice Writer is used to create a text document. The document is stored as a file in the computer with the extension .odt. For example, a document stored as a file Anita.odt. File tab contain, New, Open, Close, Save etc.

a. New – It is used to create a new file, Steps for creating new file is –
File >> New
b. Save As – When we want to save file first time or we want to save file in different file name, then you can use Save As
File >> Save As

c. Page Preview – Print preview helps to see how the printed page will look like after prining. Steps to use print preview are –
File >> Page Preview

d. Printer Setting – You can make settings for the printer using printer setting.
File >> Printer Setting

e. Print – Print the document to the connected printer. You can select the size of the paper, print multiple apges on a single sheet etc.
File >> Print

Edit Tab

The Edit tab consists of commands required to perform editing on the current document. It contains several commands.

a. Move Text – Remove the text to be moved by selecting the text and then applying File -> Edit -> Cut. Then take the cursor to the place in document where you want to move the text. Then do File -> Edit -> Paste.

b. Copy Text – Select the text to be copied and then apply the commands File -> Edit -> Copy. Then take the cursor to the place in document where you want the copied text. Then do File -> Edit ->Paste.

c. Find and Replace – This is used to find words and then replace it with the new one . This option is useful to find word at multiple places in the document and replace all of them with the new one.

View Tab

The View tab consists of commands required for viewing the current document on the screen.

a. Toolbars – Select View >> Toolbars. A drop down menu appears. Select the toolbars that you want to be displayed on the screen. A displayed toolbar shows the icons for the commands.

Insert tab

The Insert tab consist of commands required for inserting different elements in a document.

a. Insert Header – Insert >> Header >> Default, A header box opens in the upper part of the document. Enter the content you want to write in a header.

b. Insert Footer – Insert >> Footer >> Default, A footer box opens in the lower part of the document. Enter the content you want ot write in the header.

c. Insert Fields – Insert >> Fields, A pop-up menu appears and select the eleemnt to be inserted. The selected element will insert at the location of the cursor.

d. Insert Hyperlink – Insert >> Hyperlink, A dialog box opens. On the left side of the dialog box, select where you want to link – a webpage, docuemnt, mail or to a new document.

e. Insert Table of Content – Insert >> Indexes & Tables, Select Table of content. Click Ok. A table of content will be inserted in your document.

f. Insert Table – Insert >> Table, A dialog box appears. Enter the table name, numbers of rows and columns. Click Ok. A table will be inserted in the document.

g. Insert Formula – Insert >> Object >> Formula, A pop up menu of element appears then select the eleemnt and write the formula.

Format Tab

The Format tab consist of commands required for formatting the document.

a. Format Character – Format >> Character, A dialog box contain font type, typefae, and size, you can also give font effects and backgound.

b. Format Paragraph – Format >> Paragraph, With the help of Format paragraph you can change the indentation and spacing, border, alignment, etc.

c. Format Bullets and Numbering – Format >> Bullets and Numbering, You can select bullets of different kinds or numbering. In the document the bullets are inserted at the location at which the cursor is present.

d. Format Page – Format >> page, This allows to format the whole page – borders, color, alignment, number of columns etc.

e. Change case – Format >> Change case, there are 6 different types of change case available in digital documentation.

Table Tab

The Table tab consists of commands that operate on a table.

a. Convert Table to Text or Text to Table – Table >> Convert, If text is to be converted to table, the text to table option appears, select it to convert text to table, if a table is already present, then table to text option appears.

Tools Tab

The Tools tab consists of commands that can be used on the document for better results.

a. Check spelling and grammar – Tools >> Spelling and Grammar, The grammar and spelling you can check with the help of Spelling and Grammar option.

b. Find Number of Words – Tools >> Word Count, if the text is already selected, then word count displays the number of words and characters in the selected text.

Window Tab

The Window tab consists of commands that work on a window. The commands in this tab allow the user to open a new window or close an existing window. Also, the name of all currently open windows is also displayed.

Help Tab

The Help tab consists of commands that provide help to the user of the OpenOffice Writer software. On clicking on the help tab appears. You can browse the Help for the command you want.

Spreadsheet OpenOffice Calc

Spreadsheets are used in various fields such as banking, finance, accounting, and education.

Following are some of the popular uses of spreadsheets –

1. Managing financial data such as bank account information, budgets, transactions, billing, and receipts.
2. Handling inventory, reviews, employee information, surveys, etc., using data entry forms.
3. Tracking student performance by calculating grades and other relevant information such as attendance, highest score, and lowest score.
4. Creating lists of items which may not be numeric such as student list, grocery list.
5. Managing company information such as profit and sales by creating graphs from the data.

Main Features of OpenOffice Calc

Starting Calc

To start OpenOffice Calc, there are various ways in which you can start it –
a. As a Windows application, you can click Start -> Programs ->OpenOffice
b. If the OpenOffice icon as shown in Figure 4.2 is on the desktop, double click the icon.

Calc Main Window

Title Bar – The title bar at the top displays the information about the spreadsheet such as name of the current spreadsheet (ExampleSheet), extension of the spreadsheet (.ods), and name of the software (OpenOffice Calc).

Menu Bar – Just below the title bar is the menu bar. It contains various menu options.

• File – It contains commands to create a new file.
• Edit: It contains commands to edit a file such as Cut, Copy, Paste, Paste Special, Select All, Find & Replace, Delete Contents, Delete Cells, Headers & Footers.
• View – It contains commands to modify the view of the Calc such as Toolbars, Full Screen, Zoom.
• Insert – It contains commands for inserting Cells, Rows, Columns, Sheet, Sheet From File, Function, Function List, Picture, Chart etc.
• Format – It contains commands to alter the layout of the spreadsheet such as formatting Cells, altering Rows, Columns, Sheet.
• Tools – It contains options to o spellcheck (Spelling), insert macros (Macros) etc.
• Data – It contains commands to manipulate data such as Sort, Filter, Validity.
• Window – It contains commands to modify the window such as New Window, Close Window.
• Help – It contains the options getting help related to OpenOffice Calc such as OpenOffice Help.

Standard Bar – It lies below the Menu bar. It contains icons which perform similar operations as contained in the Menu bar options such as New, Open, Save, Print, Page Preview, Cut, Copy, Paste, Sort, Chart, Find & Replace, Spelling.

Find Bar – It contains a text box which can be used to enter text which is meant to be searched in the spreadsheet.

Formatting Bar – In the Formatting toolbar, the leftmost icon is for the Style & Formatting and the following two boxes are the Font Name and Font Size lists.

Formula Bar – On the left side of the Formula bar is the Name box which contains a letter and name combination such as C4, whenever you select a cell on the spreadsheet. This combination is called Cell Reference.

Sheet Tabs – A single spreadsheet Calc file can contain multiple sheets. You can traverse individual sheets by using the Sheet tabs. The current active sheet has a white tab.

Status Bar – Status bar at the bottom provides information about the spreadsheet and convenient ways to quickly change some of its features.

Sidebar – Located on the right side of the edit views of Calc, sidebar contains frequently used tools grouped in decks such as Properties, Styles and Formatting, Gallery, Navigator. Clicking on any of the vertical tabs opens the deck for that tab.

Active Cell – When you select a cell, you will notice a heavy black border around the selected cell as shown in Figure 4.3. The heavy black border indicates that selected cell is the active cell.

Row Headers – Row headers are in the form of numbers -1,2,3…. which are present at the left of each row.

Column Headers – Column headers are in the form of alphabets – A,B,C,…shown at the top of each column.

Working with Data

Data – There are various types of data that can be entered in a cell:

1. Labels – These are alphabetic or alphanumeric entries without numeric value. They can be a combination of letters, numbers, space, special characters etc. Labels are left justified by default.
2. Numbers or Values – These are numeric data which may be integers or can contain decimals or fractions. Values are right-justified by default.
3. Formulas – Used to perform calculations such as addition, subtraction, multiplication, division, average. Formulas must begin with an = sign.

Moving Data within a Spreadsheet – For moving data from one cell to another we have the cut-copy-paste functions. 

Using AutoFill – Using this function in Calc, data is generated automatically depending on a specified series. The act of entering numbers into a table’s serial number (S.No) column is a very typical example. This column, which is quite commonly used, typically carries a series of numbers. Use Calc’s AutoFill command to fill in the serial numbers (let’s say 1 to 100) automatically.

Formatting Data

Formatting a document means adding elements of style and presentation to documents to improve the readability and make them more attractive.

Numbers as Text – Calc evaluates each cell and determines whether the entry is a Value or Label. Cells containing a combination of values and text is automatically treated as a label.

Font – Font refers to the design for a set of characters. It is the combination of typeface and other qualities, such as size, pitch, and spacing. The font can be changed from the Formatting bar. 

Font Name – Various font types are there in Calc such as Arial, Arimo, and Century Schoolbook L.

Gridlines and Borders – The gray gridlines (vertical and horizontal lines) that you can see in a Calc spreadsheet help you while you’re working in a spreadsheet. Gridlines appear automatically showing you how the data is organized into rows and columns.

Flow of Text – In order to control the flow of text within cells, Calc provides various ways –

• Merging / Splitting Cells – In order to merge cells, select the cells and click on the Merge Cells icon in the Standard Bar. To split the merged cells, select the cell and click on the Merge Cells icon.
• Wrap Text – It means to break the text into multiple lines i.e. adjusting the row height to fit the text within the cell but keeping the column width of the cell same. Steps to wrap text:

1. Right-click on the cell.
2. Select the option – Format Cells.
3. A dialog box opens up. Open the Alignment Tab and check the option – Wrap text automatically

Shrink to Fit – This option shrinks the text to fit in the size of the existing cell. In this case neither the row height nor the column width is changed. The text size is decreased according to the cell. Steps to shrink the text size to fit the cell:

1. Right-click on the cell.
2. Select the option – Format Cells.
3. A dialog box opens up. Open the Alignment Tab and check the option – Shrink to fit cell size

Numeric Data Formatting – 

Some of the commonly used number formats are discussed below –

• Currency – In the currency format, you can prefix or suffix currency symbols to the numeric data.
• Percent – It displays the number as a percentage. Two decimal places are added to the number and the percent symbol (%) is suffixed at the end.
• Standard – It sets the number in the cell to the default format by removing any other numeric formatting applied.
• Decimals – Decimal places can be inserted or removed by using the Add Decimal place or Delete Decimal place icon respectively.
• Date – By default, the date format in Calc is dd/mm/yy. But in case you want to change the format, you can find various date formats in the Format Cells dialog box.

Functions

Commonly used mathematical functions in Calc – 

• SUM(n1;n2…) – To calculate the sum of arguments n1, n2…
• PRODUCT (n1; n2…) – To calculate the product of arguments n1, n2…
• SQRT (n) – To calculate the square root of a number n.
• POWER (n; p) – To calculate power p of a number n.
• LOG (n; b) – To calculate log a number n to base b.
• ROUND (n; d) – To round a number n to digits d.
• SIN (n), COS (n), TAN (n) – To calculate sine, cosine and tangent of n.
• RAND BETWEEN (f; l) – Returns a random number between f and l.
• QUOTIENT (a; b) – To calculate integer quotient of division a/b.
• ABS (n) – To calculate the absolute value of a number n.

Absolute and Relative Addressing

Relative Addressing

The method of addressing instructions and data sections by specifying their location in reference to the location counter or to some other symbolic location is known as relative addressing. This kind of addressing is never done in bits, words, or instructions; it is always done in bytes.

Absolute Addressing

When you wish to fix the location of a cell, you utilise absolute references. A dollar sign is placed before each of these cell references. You are fixing the value of a specific cell reference by doing this. For instance, the formula will become = B1+B2 if you enter = A1+A2 into A3 and duplicate it to another location: B3.

Mixed Addressing

Various references An absolute reference and a relative reference combine to provide a mixed reference in Excel. This indicates that a portion of the reference, either the row or the column, is fixed, while the remaining portion is relative.

Sorting and Filtering Data

Sorting – The Sort Ascending and Sort Descending commands on the Standard toolbar, as well as the Data menu, which opens a dialogue box with extra options, make it simple to arrange data in Calc.

Steps to sort data in ascending order using the Standard Toolbar –

Step 1: Select the cells you want to sort.
Step 2: Click on the Sort Ascending icon on the Standard Toolbar.
Data will be sorted according to the first column of the selected cells.

Steps to sort data in ascending order using the Sort command –

Step 1: Select the cells you want to sort.
Step 2: Click on the Sort option in the Data menu which opens a dialog box.
Step 3: You can change the select the column based on which you want to sort the data. Also, you can select the Ascending or Descending option.
Step 4: Click on OK.

Filtering Data  – Applying a filter means displaying data based on some conditions or filters. Filters can be applied by using the Filter option in the Data menu.

Three types of filters can be applied – AutoFilter, Standard Filter and Advance Filter. Let us study AutoFilter and Standard filter in detail –

AutoFilter – This filter is added on the topmost row of the selected data in the form of a drop down list from which you can select data to be displayed or in other words apply filters.

Step 1: Select the data.
Step 2: Select Data menu and click on Filter->AutoFilter.
Step 3: On the topmost cell of each column you will observe drop-down boxes.

Standard Filter  Standard filter is used to provide more options for filtering such as combining multiple filters by using AND and OR operator. AND operator implies that all the filters must be satisfied for displaying the data. OR operator implies that at least one filter should be satisfied for displaying the data.

Creating Charts and Graphs

In Calc, you can create graphs and charts to represent the data graphically. Sometimes, it is very difficult to analyze spreadsheets containing huge amount of data.

Creating Charts 

Following are the steps required to insert a chart –

Step 1: Select the data which is to be included in the chart.
Step 2: Go to the Insert menu and select the Chart option. 

Step 3: Chart wizard dialog box is displayed

Step 4: Select the chart type (Column chart, Bar chart, Pie chart etc.) and click on the Finish button

Spreadsheet different type of chart

Column Chart – A Column chart is used to compare values across categories by using vertical bars. The Column chart can be inserted by selecting the Column option in the Chart type of the Chart Wizard.

Bar Chart – A Bar chart is the horizontal version of a column chart. It is used if you have large text labels.

Pie Chart – A Pie chart is used to display the contribution of each value (slice) to a total (pie) i.e., it can be used to plot various pieces of a single entity.

Line Chart – A Line chart is used to compare trends and changes in values over time.

Scatter Chart – A Scatter chart is used to display relationships between variables.

Macros

Every command and action you take to complete a task is recorded in a macro. Using a macro, you can later replay the mouse movements and keystrokes you made while working. The macro replays those actions in the exact same sequence as you ran them. Therefore, you only need to execute the macro if you wish to repeat the activities numerous times.

Create/Record Macros:

Step 1 : Go to the Tools tab on the Menu bar->Macros->Record Macro

Step 2 : Calc has started recording the Macro. Until you stop the recording, every Calc command and keystroke will be recorded in the macro, in the order in which they are entered.

Step 3 : After we have done all the required tasks, we will stop recording the macro by clicking on the Stop recording option on the dialog box.

Run/Use Macros created:

Step 1 : Go to the Tools tab on the Menu bar->Macros->Run Macros

Step 2 : A dialog box will open as showing all the macros created.

Step 3 : The tasks performed during recording of the macro will be repeated in the same order in which they were performed.

OpenOffice Impression 

The development of presentations for a bigger audience requires presentation software. With the use of the presentation software, users may make presentations that include sound, text, movies, photos, and tables.

Slide Show Tab

Slide Show Settings – Slide Show -> Slide Show Settings. A dialog box opens . Select the slide to start from, animation allowed etc.

Custom Animation – Slide Show -> Custom Animation.A dialog box opens on the right side of the screen. Select the element on the slide on which the animation has to be applied. Click . Select the animation to be applied.

Slide Transition – Slide Show -> Slide Transition. A dialog box opens on the right side. Select the transition you want to apply to the slide.

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Networking and Internet Class 11 Notes. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

Networking and Internet Class 11 Notes

Evolution of Networks and Internet

The idea of the Internet was developed in 1969, and since then, it has undergone a number of technological and infrastructure modifications, as will be explained below: The idea behind Advanced Research Project Agency Network served as the basis for the creation of the Internet (ARPANET). The American Department of Defense created ARPANET.

TCP/IP (Transmission Control Protocol/Internet Protocol) was created in 1970 in response to the need for communication among multiple heterogeneous networks. The U.S. National Science Foundation created NSFNET, a large network, along with many other smaller networks, in 1984 for use in research and teaching. The network grew significantly once ARPANET and NSFNET were linked. The TCP/IP protocol (communication rules) served as a glue to join different heterogeneous networks into a single network. The Internet (a network of networks) is this large network.

Computer Network

Electronic equipment that exchange data or messages with one another, such as computers, printers, fax machines, and telephones, are referred to as nodes or stations.

a. Sender – The node that is responsible for sending the data.
b. Receiver – The node that is responsible for receiving the data.
c. Message – Message is the information or meaningful data that is being communicated in a structured form.
d. Channel – Channel is the communication medium through which message is transmitted

A computer network is made up of a number of connected nodes that communicate over a channel. There are three types of computer network communication:

1. Simplex
2. half-duplex
3. full-duplex

1. Simplex – Information can only be transmitted in one way in simplex mode. It is known as a unidirectional mode. The data transferred via numerous fibre optics and satellites in computer networks is straightforward in nature.

2. Half-duplex – Only one node at a time can broadcast data in the half-duplex mode, which allows for bidirectional communication between the two nodes. In low-bandwidth situations, this mode is typically used to transfer files between nodes.

3. Full-duplex – In full-duplex mode, both communicating parties can send and receive at the same time. NIC (Network Interface Card) supports full-duplex mode.

Transmission Medium

The channel of transmission through which data can be sent as a signal from one node to another is referred to as a transmission medium.

There are two type of transmision medium –

• Guided Medium
• Unguided Medium

1. Guided Medium – In guided medium, the data transmitted in a cable system that has a fixed path. for example Co-axil, UTP, Optical fiber cable, etc.

2. Unguided Medium – In Unguided medium, the data transmit through free space in the form of electromagnetic signal. for example, radio waves, lasers, micro waves etc.

Network Devices

Repeater – With increase in distance, a signal may become weak and distorted. A repeater is used to restore the input signal to its original form, so that it can travel a larger distance.

Hub – A hub joins multiple lines, sometimes known as cable segments, as opposed to a repeater which links only two wires. A hub has multiple input/output (I/O) ports, each of which is connected to a single device.

Bridge – In order to create a larger local area network (LAN), smaller LANs can be combined using bridges, which are multiport devices used to connect two or more LANs.

Switch – Switches are used to connect individual nodes in the network with one another, as opposed to bridges, which join two or more LAN segments.

Router – Routers are used to link different networks (LAN or WAN) collectively. Data from an incoming network is sent to another network via a router. A router keeps track of different networks’ routing tables. The router chooses which network the incoming packet should be sent to based on the destination address.

Gateway – A gateway enables communication across networks based on various protocol systems. Data from one network that uses one protocol is translated to the outgoing network’s protocol before being forwarded.

Network Types

On the basis of geographical span, network can be broadly categorized as PAN, LAN, MAN, and WAN.

Personal area network – An individual’s workspace can be connected to a computer network called a personal area network (PAN) . for example, connection between PCs and smartphone, PCs and tables, PCs and printer etc.

Local area network – Local Area networks are private networks and can span a radius of up to 1 Km. They are generally established within a building or campus. LANs operate at a speed in the range 10 Mbps to 1 Gbps.

Metropolitan Area Network – These networks, which have a radius of up to 50 km, are used to create connections within cities. Resources can be shared more easily because to MANs, which link different local area networks. a city-based cable television network, as an example.

Wide Area Network – A WAN typically covers a distance of roughly 1000 km. They are useful for linking isolated places and for long-distance communication. They create connections inside a nation or continent. A WAN may be owned and operated by a number of different companies. It links numerous metropolitan and local area networks.

Topology

Network topology refers to the positioning of nodes in a network, often known as their layout. or the arrangement of nodes in a network is called network topology. there are two type of topologies – 

• Broadcast – All nodes share the same physical link one node transmit and other receive. for example, Bus and Ring topologies. 
• Point to point – Every pair of nodes has a dedicated link. for example, Star and Mesh topologies. 

Bus Topology

In a bus topology, several nodes are connected by a lengthy cable known as the backbone cable (or just the backbone) using a connector known as the tap. This topology requires less cabling and is easy to install and extend the network laid using it. However, fault detection and isolation is difficult.

Ring Topology

In a ring topology, all devices are connected by a cable that forms a ring. The intended recipient of the message is reached by way of a one-way transmission of the intended message. The  problem of network is it take longer time to send a message from one node to another node.

Star Topology

All of the devices in a star topology are connected to the hub, which serves as the central controller. Any two devices can communicate with each other through the hub that relays messages. Installation and configuration of the star network are simple.

Mesh Topology

In a mesh topology, every node in the network is linked to every other node. The topology offers secure data transfer without any traffic issues because every conceivable pair of nodes has a dedicated point-to-point connection.

Tree Topology

A hybrid topology that combines bus and star topologies is called tree topology. In a bus topology, the primary backbone cable functions as the tree’s trunk, and star networks (and even individual nodes) are connected to it like the tree’s branches.

Identification of computers and users over a network

MAC Address

A network interface controller (NIC) is given a media access control address (MAC address), which it can use as a network address in communications inside a network segment. Ethernet, Wi-Fi, and Bluetooth are just a few of the IEEE 802 networking technologies that frequently employ this application.

MAC addresses are 12-digit hexadecimal (or 48 bit) numbers. By convention, MAC addresses are usually written in one of the following two formats:
MM:MM:MM: SS: SS:SS
MM-MM-MM-SS-SS-SS

IP Address

Every computer in a network has an additional unique identification code called an IP Address. The four bytes (or 32 bits) that make up an IP address can range in value from 0 to 255. A typical IP address appears as follows:
59.177.134.72
IP addresses are typically written in decimal format as a “dotted decimal number” like the one above to make them simpler for humans to remember.

Domain Name

An Internet physical IP address is linked to an easy-to-remember name known as a domain name, which is frequently just referred to as a domain. It is the distinctive name that follows the @ symbol in email addresses and the www. prefix in web addresses.

Names and Country-Specific Domain Names. For example
Generic Domain Names:
·com – commercial business
·edu – Educational institutions
·gov – Government agencies
·mil – Military
·net – Network organizations
·org – Organizations (nonprofit)

Country Specific Domain Names:
.in – India
·au – Australia
·ca – Canada
.ch – China
.nz – New Zealand
.pk – Pakistan
.jp – Japan
.us – United States of America

Domain Name Resolution

The process of turning a domain name into an IP address is known as domain name resolution. Since one IP address can correlate to many domain names and one domain name to one IP address, multiple domain names can simultaneously be resolved to the same IP address.

Internet and its Terminology

Digital literacy

The capacity to use reading, writing, technological expertise, and critical thinking to navigate our digital world is known as digital literacy. It involves using technology to find, assess, and transmit information, including devices like a smartphone, PC, e-reader, and more.

Internet Services

Network services are programmes that are hosted by servers on a computer network and offer functionality to network users. The Internet has several uses, including e-mail, file sharing, remote login, and the World Wide Web (WWW).

• Electronic Mail (E-Mail) – A multimedia attachment, such as text, audio, an image, or a video, may be included with an email in addition to being a textual message. The email may be sent to one or more intended recipients by the sender.
• File Transfer – FTP is used to transfer files from one computer to another using a TCP-based network (File Transfer Protocol). Client-server architecture is the foundation of File Transfer Protocol.
  Local hosts (clients) can download or upload files to distant hosts using FTP (server).
• Remote Login (TELNET) –The acronym for this network is TELNET. It is a client-server programme that enables users to connect to remote systems while logged in to one system.
• World Wide Web (WWW) – The World Wide Web (WWW), also referred to as the “web,” is a collection of connected information stored on devices that are dispersed across the Internet.

Internet Protocol Suite

Protocol is set of rule, The common network model and communication protocol stack used on the Internet and in the majority of other computer networks is known as the Internet Protocol Suite (IP suite). The IP suite is largely the global standard for computer-to-computer communication, despite the existence of alternate networking paradigms.

These sub-tasks or functions are performed by different layers of TCP/IP mode

Application layer

Data or a message is formed at the sending end and reviewed and processed at the receiving end. The message that will be sent with the header must likewise be enclosed by this layer. On this layer, a number of protocols like HTTP (HyperText Transfer Protocol) and POP3 (Post Office Protocol version 3) operate. 

Transport layer

The message is sent from the application layer to the transport layer, which appends the source and destination ports of the processes at the two ends. At this layer, two end-to-end protocols—TCP and UDP—are in use. When timely and error-free data transport is crucial, TCP (Transmission Control Protocol) is a dependable connection-oriented protocol that is required.

Internet Layer

The Internet layer receives the segments from the transport layer and adds the source and destination machine network addresses (also termed IP address). IP, or Internet Protocol, is utilised at the Internet layer. The format of packets sent over the Internet is specified by IP.

Link layer

Host to Internet layer is another name for link layer. The header containing the sender and receiver physical addresses must be included by this layer to the packet that was received from the Internet layer.

Cyber Threats and Cyber Security

Malwares

Malicious software (programmes) created with the purpose of interfering with system performance by harming the system, gaining unauthorised access to the system, or preventing legitimate users from using computing resources are referred to as malware. Malware includes viruses, worms, and Trojan horses.

Virus – A virus is a software code that may harm your system by overwriting or corrupting the system files.

Worm – A worm is often received via network, and it automatically keeps on creating several copies of itself on the hard disk thereby flooding the hard disk. When a worm is received as an email attachment, it is automatically forwarded to the recipients leading to network congestion. 

Trojan Horse – Trojan Horse is a code that appears to be desirable and useful but ends up harming the
system. Trojan horse can attach itself with a safe application. For example, it may be attached to any game downloaded over the Internet. Such an application when executed creates a backdoor in the system through which a hacker can access the system.

Eavesdropping

The act of surreptitiously or covertly listening to another person’s private discussion or communications without that person’s agreement is known as eavesdropping. Telephone lines, cellphone networks, email, and instant messaging are all used for eavesdropping.

Denial of Service

A cyberattack known as a denial-of-service (DoS) attack renders a system or network resource inaccessible to its users by temporarily or permanently interrupting services.

Phishing

The practise of stealing a user’s personal information through fraudulent mail is known as phishing.
These emails either include embedded forms that request personal information from you or include links to web pages that might ask you for it.

Cyber Crime

Cybercrimes are crimes including theft, fraud, and forgery that involve the improper use of computers or the Internet. According to the IT Act, cybercrime is any illegal activity in which a computer is either a tool, a target, or both. These crimes include some of those listed below –

1. Cyber bullying – Harassment or bullying inflicted through the use of electronic or communication devices such as computer, mobile phone, laptop, etc.
2. Cyber stalking – Use of electronic communication by a person to follow a person or attempts to contact a person to foster personal interaction repeatedly despite a clear indication of disinterest by such person.
3. Online Job Fraud – An attempt to defraud people who need employment by giving them a false hope/ promise of better employment with higher wages.
4. Vishing – To seek personal information like Customer ID, Net Banking password, ATM PIN, OTP, Card expiry date, CVV etc. through a phone call.
5. SMSing – Use of mobile phone text messages to lure victims into calling back on a fraudulent phone
   number, visiting fraudulent websites or downloading malicious content via phone or web.
6. SIM Swap Scam – Getting a new SIM card against a registered mobile number
7. Credit card (or debit card) fraud – An unauthorized use of another’s credit or debit card information for the purpose of purchases or withdrawing funds from it.
8. Identity theft – Dishonestly making use of the electronic signature, password or any other unique
   identification feature of any other person.
9. Spamming – Persuading a recipient to buy a product or service, or visit a website via email, SMS, MMS
   where he can make purchases.
10. Ransomware – The victim is asked to pay the demanded ransom to get his device decrypts.

Network Security Tools and Services

Network layer security

TCP/IP protocols may be secured with cryptographic methods and security protocol like Secure Sockets Layer (SSL).

Firewalls

An organization’s previously set security policies are used to monitor and filter incoming and outgoing network traffic through a firewall, a network security device. A firewall is essentially the barrier that stands between a private internal network and the open Internet at its most basic level.

Antivirus

Viruses and other types of dangerous software can be found and eliminated from your computer or laptop using an antivirus package. Malicious software, also referred to as malware, is computer code that can damage your computers, laptops, and the data they contain.

Password managers

A password manager is a piece of software that aids in organising and storing passwords. In order to access their complete password database from top to bottom, users of password managers typically need to generate a master password, which should be a single, extremely strong password.

Cyber Law

Cyber laws serve as a deterrent to illicit cybercrime and regulate the systematic use of e-resources, such as e-business. To prevent cybercrimes and prosecute those responsible, numerous cyber laws have also been passed. These laws specify the punishment that will be meted out to those who violate the laws.

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers

Teachers and Examiners (CBSESkillEduction) collaborated to create the Computer Organization Class 11 Notes. All the important Information are taken from the NCERT Textbook Information Technology (802) class 11.

Computer Organization Class 11 Notes

The word “computer” is derived from “compute,” which means to calculate. User input is received by the computer, which then processes it and displays output. It is a machine that follows a set of rules. It receives input from the user, processes it in accordance with the given instructions, and then outputs the result.

Using electronic signals, computers are electronic devices. The signals for on and off stand for 1 and 0, respectively. The two digits 0 and 1 are the basis for binary language, also known as machine language. Before, only binary language was used by computer specialists to communicate and train students. Many user-friendly programming languages, including C, C++, Java, JavaScript, Python, and many others, have been created. Translators are required to translate commands delivered in high level languages into binary language.

Characteristics of a Computer

Speed – Computers’ remarkable speed with which they can process data and commands is one of their most impressive features. The typical high-speed computer has a 3–4 mips (million instructions per second) processing speed.

Versatility – Computers are capable of doing multiple tasks at once. For example, you can multitask while downloading movies, playing music, and creating word documents.

Accuracy – The machine not only completes a variety of tasks quickly, but also precisely and accurately. Be aware that any faults in a computer’s output result from incorrect data entry or improperly supplied computation instructions rather than from the machine itself. This behavior is often referred to as GIGO in computer terminology (Garbage In Garbage Out).

Diligence – A computer is free from tiredness. It can operate for several hours without making any mistakes. A computer will complete every calculation with the same accuracy even if millions of calculations need to be made.

Memory – The memory of a computer is one of its distinguishing qualities. However, the main memory of the computer is volatile, meaning that it gets erased when the computer is turned off.
As a result, another type of memory that does not degrade when a computer is turned off is supplied. Floppy discs, pen drives, and portable hard discs are all examples of secondary memory.

Storage – A computer is capable of holding a vast amount of data and information for later retrieval. A computer’s memory is unlimited and does not degrade over time like a human’s does.

Intelligence – Although early computers had impressive features, one major flaw was that they were just dumb devices that were programmed to carry out certain tasks. We now have machines that can play chess against the greatest players and drive a car without a human driver thanks to the development of artificial intelligence technology.

Components of a Computer

Every task given to a computer follows an Input- Process- Output Cycle (IPO cycle). It needs certain input, processes that input and produces the desired output. The input unit takes the input, the central processing unit does the processing of data and the output unit produces the output. The memory unit holds the data and instructions during the processing.

Input

Input adds the data in the computer with the help of Keyboard or any other input deivece.

Storage

There are basically two types of computer storage devices:

Primary Memory

The CPU has direct access to information kept in primary memory. The inputs that were received during the preceding steps are kept in the computer’s random access memory (RAM). When compared to secondary storage, this storage is both more expensive and comparatively quick.
Primary memory is directly connected to the CPU.
It is also called main memory, primary memory, or working memory of the machine.

Primary memory is of two types :
RAM ( Random Access Memory) – : It is a primary volatile memory i.e. its data gets lost once the power supply is stopped.

RAM is of two types :
DRAM (Dynamic Random Access Memory)
SRAM ( Static Random Access Memory)

DRAM – DRAM is used in main memory and is less expensive than SRAM. It is slower and consumes less power than SRAM, but it has a greater capacity for data storage.

SRAM – SRAM is more expensive, consumes more power than DRAM, and is utilised in cache memory.

Secondary Storage

Secondary storage is made up of memory that is not internal to the computer system; examples include magnetic tapes, compact discs, and portable hard drives. These aren’t connected to the CPU directly.

Cache Memory

It is an extremely fast memory that is utilised to keep up with the fast CPU. It serves as a buffer and is often positioned between the CPU and primary memory. It is quite pricey but decreases the average access time to data from the main memory.

Control Unit

Coordination between a computer’s various units is the responsibility of the control unit. It manages the operations for input, processing, and output. It works with the peripheral devices, for instance, to accept input or show output. It functions as an all-encompassing manager.

Arithmetic Logic Unit (ALU)

The actual processing of data is done by the arithmetic logic unit (ALU). The data is taken from the storage unit and subjected to arithmetic operations before being compared or otherwise processed. The processed data is then transferred back to the storage.

Output

The outcome of computer processing is frequently sent to a display device, like a printer or monitor.

Inside the Computer

These days, there are many different types of computers available, including the desktop personal computer, also known as a PC, the laptop (also known as a notebook), a small computer that can easily be placed on your lap, and the tablet, a lightweight computer the size of a handbook that is frequently used for using the Internet.

The motherboard is the main circuit board of the computer. It is a small plate that houses your computer’s CPU, RAM, hard disc and optical drive connectors, expansion cards for controlling the video and audio, and connections to the ports (such as USB ports).

a. The motherboard.
b. Central Processing Unit (CPU)
c. A video card, or a graphics processing unit (GPU).
d. “Volatile memory” also applies to random access memory (RAM).
e. Storage: Hard disc drive or solid state drive (HDD)

Components of Computer Class 11 Notes

Motherboard

This is the main circuit board, which connects numerous ports, expansion cards, the CPU, RAM, connectors for optical and hard drives, and expansion cards for controlling visual and audio (such as USB ports). Every part of the computer can be connected to it.

Input Devices

Input devices takes input from the user. The input may be in the form of text, image, sound, video etc.
Following are examples of some of the input devices of computer:
– Keyboard: this is a standard input device and takes data in the form of text.
– Mouse ; it is a pointing input device.
– Webcam: it takes data in the form of video/image
– Scanner : it generally stores data in the form of graphics
– Microphone : it is used for voice input/ audio input
– Handwriting input board: it is used for giving input from

Output Devices

devices that are used to give output to the user. Output may be in the form of visuals, text, audio, printout etc. different types of output devices are there to support various types of output. Following are some examples of output devices:
– Monitor/ VDU ( Visual Display Unit) : it is the standard output device and is similar to a television screen.
– Speaker : it is an output device that gives output in the form of an audio/ voice.
– Printer : it is also a very commonly known output device that gives output in the form of print out also called as hard copy.
– Plotter : it is a large printer like device that is used to take print of large maps, architectural designs.
– Projector : it is an output device that gives an enlarged view of the output on a large screen. It is generally used for giving a view of output to a large audience.

CPU

The motherboard houses the CPU, or central processor (Central Processing Unit). The CPU coordinates with all other computer components and carries out user commands. As a result, it bears primary responsibility for the machine’s performance. Dual-core, quad-core, and octa-core processors can be categorised based on their speed, technology, and manufacturers (Intel and AMD to name just two).

Speed of processors is usually measured in megahertz (MHz) – millions of instructions per second; and gigahertz (GHz) – billions of instructions per second, is indicative of its power.

Power Supply Unit

This part of the computer is responsible for converting the alternative current power source that workplaces or houses receive into the low voltage direct current that the device needs.

Random Access Memory (RAM)

The RAM in your computer serves as a kind of temporary storage for data that is accessed by the processor. A computer system’s ability to function depends on its memory store. The operating system is loaded into RAM each time the computer is turned on. Additionally, the RAM must include the software that must be run at all times.

Hard Disk(HD)

The majority of the information kept in a computer’s C drive is kept on a hard drive. It is a fixed-inside magnetic secondary storage device for storing data that is used in computers. The application that has to be run is initially saved on the hard drive before being moved to RAM.

Every bit of information in computer is stored in terms of Bits (Binary Digits) i.e. 0s and 1s
1 nibble = 4 bits
1 byte = 8 bits
1024 bytes = 1 Kilobyte (KB) 1024 KB = 1 Megabyte (MB)
1024 MB = 1 Gigabyte (GB)
1024 GB = 1 Terabyte (TB)
1024 TB = 1 Petabyte (PB)
1024 PB= 1 Exabyte(EB)
1024 EB = 1 Zettabyte(ZB)
1024 ZB = 1 Yottabyte (YB)

Optical Storage devices

Digital video discs (DVD) and compact discs (CD) are two types of optical storage media. A DVD has a larger capacity than a CD. By placing the disc in a disc drive, you can access the data on a CD or DVD.

Operating System Class 11 Notes

The programme known as an operating system acts as a channel between computer hardware and users.
A computer uses the services of an operating system to communicate with both the hardware and the software. Popular operating systems include, for example, Windows, Linux, Unix, MS-DOS, SOLARIS, MAC OS, The father of operating systems is regarded as Gary Arlen Kildall.

Operating System as an Interface Functions of an Operating system can be broadly categorized as:

− Communication Manager
− Resource Management
− Process Management
− File Management
− Memory Management

Communication Manager – Manages the communication needs of the system, be it communicating with the peripheral devices or the internet, are addressed by the operating system.

Resource Management – The working of a computer system is predominantly dependent on how its resources are being managed. The resources that we talk of here are -the memory of the computer, the CPU time, files, secondary storage, input/output devices etc.

Process Management – A process is a program currently executing in the memory or waiting for the CPU. In a computer there are multiple processes in the system.

Memory Management – For a process to be executed, it has to be loaded in the working memory that is the RAM (Random Access Memory).

File Management – Operating system takes care of all the files and folders (directories) maintained on the computer disk. The basic tasks that a user needs to perform on files are creation, renaming, deletion, copying or moving of a file or folder.

Types of Operating system

Operating systems can be classified in different ways; depending on various parameters.

Single-tasking and Multi-tasking

Single Task Operating System – These operating systems only permit the execution of one programme at a time.

Multi-tasking Operating System – An operating system that supports multiple tasks can run multiple programmes at once. Various processes share the processor time in this scenario.

Single user and Multi-user

Single user Operating System – Operating systems for one user only permit one user to use the system at a time. The desktop systems are within the category of standard single user systems.

Multi-user Operating System – By keeping track of every user who has registered, multi-user operating systems enable several users to access the system simultaneously.

Real-Time Operating System

Real-time operating systems are defined as those that provide a constant response time. They are designed for applications that require speedy, minimal delays in the processing of data.

Batch Processing Systems

Similar jobs are grouped together and sent to the processor as a block for processing in a batch processing system. User involvement in such systems is low. One by one, the tasks are selected and carried out.

Session 4: Troubleshooting and utilities

Common Troubleshooting Steps

As soon as the system is turned on, the power supply recognises the CPU and peripherals. Most computers will beep when the system boots up if all peripheral devices have been correctly detected. Try the following if any connected device—such as a keyboard, mouse, printer, and monitor—fails to turn on:

Check the Cables connection
Use Operating System Help to identify the problem
Check the Error Messages and act acodianly

Troubleshooting Hardware Problem

Monitor is not Showing any Display/ The Screen is Blank

If the display is not showing, you can check –
a. The System is in Sleep Mode
b. The wire is connected properly
c. Check the Laptop battery is charged or not

Keyboard Troubleshooting

If the keyboard is not responding, try the following:
a. Check the cable connection
b. Check for any damage
c. Check the batteries if wireless keyboard
d. Check weather key is not stuck

Mouse Troubleshooting

In case the mouse is not working, try the following troubleshooting options:

a. Check the cable connection

b. Check for any damage

c. If coddles moue then check the battery

d. Clean the mouse if dust is there

Troubleshooting Printer Problems

Troubleshooting if Printer is Not Responding

a. Check weather Printer is Not Connected Properly or Not Switched On

b. The Printer is Out Of Paper

c. The Printer Paper Jam

d. The Ink Cartridge of Printer is Empty

e. Incorrect Printer Driver

Printer is Slow

By lowering the printing quality and using Fast Draft/Fast Printing, the printing speed can be increased. This is effective for routine printing. Make Fast Draft the default printer quality option instead of Normal.

Sound Troubleshooting

a. Check Speaker Volume

b. Check Audio Player Controls

c. Check the Cables

d. Check the Sound Using Headphones

An Application is Running Slow

Check for Available Updates

Check for updates if restarting the application does not increase performance. Look for the option to check for updates under the Help menu. If this choice is not available, You can look for application updates online.

An Application is Frozen

An application might freeze occasionally. You won’t be able to click any application buttons or close the window when this occurs. You might try the following troubleshooting techniques –

Utilities

Utilities are the special programs that help computer systems to work more smoothly, efficiently and effectively. Utility software programs help in :

– improving the performance of computer
– provide security from virus,
– manage disk space
– free disk space on hard Disk – provide backup etc.

Check Minimum Free Disk Space Required

On your system, there should be between 200 and 500 MB of free hard drive space. The lack of available free space inhibits the computer’s operation. Open the Windows Explorer application and select My Computer to see the available disc space. This will display the various hard disc partitions, including C and D.

Delete Unused Files and Programs

Delete unnecessary files and programmes on a regular basis. Your disk’s free space will rise as a result, improving computer performance. Images and movies occupy a large amount of storage. You can transfer these to an external drive.

Empty Your Recycle Bin

This can be done by right-clicking on the Recycle Bin icon (usually on the desktop), and then selecting Empty Recycle Bin.

Remove Temporary files

It is important to periodically remove the temporary files and the Internet browsing history. This too will increase the free space on your disk.

Disk Defragmentation

The data in our files is always changing. As a result, the memory file becomes incomplete or has gaps in it (hard disk). As a result, the file uses up more space on the computer, which could slow it down. To regain this space, you must use a disc defragmentation application. The next steps can help you do that.

− Open the Windows Explorer Application and click on My Computer.
− Highlight the C drive and right click to get a pop-up menu.
− Select the Properties option from this popup Menu.
− The dialog box showing the properties of the local disk (C:)

Troubleshooting Networking Problems

Points to Remember:

– Computer is an electronic device that takes input from the user, processes it and displays output.

– The on and off signals denote 1 and 0 respectively. The binary language, also called machine language,

– Commands given in high level languages need to be converted into binary language with the help of translators.

– Speed, accuracy, memory, diligence, versatility are some of the features of computer.

– Hardware are the physical components of a computer like motherboard, memory devices, monitor, keyboard etc.

– Software is the set of programs or instructions.

– It is sometimes difficult to judge if the problem is hardware-related or software related. Identify the part of the computer system that is not functioning properly.

– Before handing over your machine to an engineer, take a backup of important files to another source, like a pen drive or an external hard disk. This would ensure a copy of your data is available, in case something unforeseen happens while your computer is being repaired.

– Most systems produce a beep when a system boots successfully (i.e. all peripheral devices have been successfully detected). If any connected device does not switch on, try the common troubleshooting tips: close running programs that are not being currently used; check the cables; repeat to see if the problem recurs; use help; record error messages and restart the computer.

– If the monitor is not showing any display or the screen is blank: the system could be in sleep mode; check all the connections; the laptop’s battery may be low. If the keyboard is not responding: check connections; check for any damage; try changing batteries in a wireless keyboard; the keys may be stuck, replacing the keyboard.

– In case the mouse is not working: check connections; check for any damage and replace the mouse if required; restart the cordless mouse; clean the mouse.

– The printer may not be responding because: it may not be connected properly or not switched on; the printer could be out of paper; there could be a paper caught in the printer; printer’s ink cartridge could be empty; an incorrect printer driver may be configured.

– The printer and computer may not be communicating properly when a wireless connection is being used to connect a PC/ laptop to a printer. The IP address configured on your computer should match the Dynamic IP address allocated to the printer.

– When the print jobs are being sent to the wrong printer: change the default printer or choose an alternate printer for the current print job.

– To improve the printing speed, reduce the printing quality by using Fast Draft/ Fast Pri nting.

– When there is no sound from the speakers: check speaker volume; check audio player controls; check the cables; check the sound using headphones.

– When an application is running slow, check for available updates.

– Sometimes an application may freeze. Forcefully end the application or restart the computer.

– When all programs on the computer run slowly, check for viruses or try freeing space on the hard disk.

Employability Skills Class 11 Notes

• Unit 1 : Communication Skills Class 11 Notes
• Unit 2 : Self-Management Skills Class 11 Notes
• Unit 3 : Information and Communication Technology Skills Class 11 Notes
• Unit 4 : Entrepreneurial Skills Class 11 Notes
• Unit 5 : Green Skills Class 11 Notes

Employability Skills Class 11 MCQ

• Unit 1 : Communication Skills Class 11 MCQ
• Unit 2 : Self-Management Skills Class 11 MCQ
• Unit 3 : Information and Communication Technology Skills Class 11 MCQ
• Unit 4 : Entrepreneurial Skills Class 11 MCQ
• Unit 5 : Green Skills Class 11 MCQ

Employability Skills Class 11 Questions and Answers

• Unit 1 : Communication Skills Class 11 Questions and Answers
• Unit 2 : Self-Management Skills – III
• Unit 3 : Information and Communication Technology Skills Class 11 Questions and Answers
• Unit 4 : Entrepreneurial Skills Class 11 Questions and Answers
• Unit 5 : Green Skills Class 11 Questions and Answers

Information Technology Class 11 Notes

• Unit -1 : Computer Organization Class 11 Notes
• Unit -2 : Networking And Internet Class 11 Notes
• Unit-3 : Office Automation Tools Class 11 Notes
• Unit-4: RDBMS Class 11 Notes
• Unit-5: Fundamentals of Java Class 11 Notes

Information Technology Class 11 MCQ

• Unit -1 : Computer Organization Class 11 MCQ
• Unit -2 : Networking And Internet Class 11 MCQ
• Unit-3 : Office Automation Tools Class 11 MCQ
• Unit-4: RDBMS Class 11 MCQ
• Unit-5: Fundamentals of Java Class 11 MCQ

Information Technology Class 11 Questions and Answers

• Unit -1 : Computer Organization Class 11 Questions and Answers
• Unit -2 : Networking And Internet Class 11 Questions and Answers
• Unit-3 : Office Automation Tools Class 11 Questions and Answers
• Unit-4: RDBMS Class 11 Questions and Answers
• Unit-5: Fundamentals of Java Class 11 Questions and Answers