FULL FORMS
The Bold type are specially important for
SLC questions
3D: Three Dimension
4GL: Fourth Generation Language
ABC: Attansoff Berry Computer
ADSL: Asynchronous Digital Subscriber Line
AI: Artificial Intelligence
ALGOL: Algorithmic Oriented Language
ALR: Advanced Logic Research
ALU: Arithmetic and Logical Unit
AM: Amplitude Modulation
ANSI: American National Standard Institute
ARCNet: Attached Resource Computer Network
ARPANet: American Advanced Research Project
Agency
ASCII: American Standard Code for
Information Interchange
AT & T: American Telephone and
Telegraph System
AT: Advanced Technology
ATM: Automated Teller machine
B2B: Business to Business
BASIC: Beginner’s All Purpose Symbolic
Instruction Code
BCD: Binary Coded Decimal
BCPL: Beginners Cambridge Programming
Language
BCR: Bar Code Reader
BIOS: Basic Input Output System
Bits:Binary Digits
BMP: Bitmap
BNC: British Naval Connector
BOF:Beginning of File
BPI: Bytes Per Inch
BPS: Bit Per Sector
CAD: Computer Aided Designing
CAI: Computer Aided Instruction
CAL: Computer Aided/Assisted Learning
CAM: Computer Aided/Assisted Manufacturing
CAN: Computer Association of Nepal
CAT: Computer Aided/Assisted Training
CAVE: Cave Automatic Virtual Environment
CBE: Computer Based Education
CBT: Computer Based Training
CC: Computer Consultancy
CD-ROM: Compact Disk Read Only Memory
CESIL: Computer Education in School
Instruction Language
CGA: Color Display Adaptor
CIS: Computer Information System
CISC: Complex Instruction Set Computer
CMOS: Complementary Metal Oxide
Semiconductor
COBOL: Common Business Oriented Language
CODASYL: Conference Of Data Systems
Language
COM: Computer Output to Microfilm
CP/M: Control Program For Microprocessor
CPAV: Central Point Anti Virus
CPS: Character Per Second
CPU: Central Processing Unit
CRT: Cathode Ray Tube
CSMA/CD: Carrier Sense Multiple Access with
Collision Detection
CSU/DSU: Channel Service Unit / Digital
Service Unit
CUI: Character User Interface
DBMS: Database Management System
DCU: Device Control Unit
DDE: Dynamic Data Exchange
DIMM: Dual In Line Memory Module
DIX: Digital Intel and Xerox
DNA: Digital Network Architecture
DNS: Domain Name Server
DRAM: Dynamic Random Access Memory
DRPA: Defense Advanced Research Project
Agency
DSDD: Double Sided Double Density
DSHD: Double Sided High Density
DSI: Data System International
DSSD: Double Sided Single Density
DVD: Digital Versatile Disk
EBCDIC: Extended Binary Coded Decimal
information Interchange.
EDO-RAM: Extended Data Out Random Access
Memory
EDS: Electronic Data Storage / Exchangeable
Disk System
EDSAC: Electronic Delay Storage Automatic
Computer
EDVAC: Electronic Discrete Variable
Automatic Computer
EEPROM: Electrically Erasable Programmable
Read Only Memory
EGA: Enhanced Graphic Adaptor
eGMP: Electronic Government Master Plan
EICA: Engine Indicator and Crew Alert
System.
EISA: Extended Industry Standard
Architecture
E-mail: Electronic mail
EMI: Electro Magnetic Interference
EMS: Expanded Memory
ENIAC: Electronic Numerical Integrator And
Calculator
EOF: End of File
EPROM: Erasable Programmable Read Only
Memory
FAQ: Frequently Asked Questions
FAT: File Allocation Table
FAX: Facsimile
FDD: Floppy Disk Drive
FDDI: Fiber Distributed Data Interface
FDS: Fixed Disk System
FM: Frequency Modulation
FMC: Flight Management Comptuer
FORTRAN: FORmula TRANslation
FPM RAM: Fast Data Page Random Access
Memory
FTP: File Transfer Protocol
G2C: Government to Citizens
G2G: Government to Government
GaAs: Gallium Arsenide
GB: Giga Bytes
GIF: Graphics Interchange Format
GIGO: Garbage in Garbage Out
GIS: Geographical Information System
GPL: General Public License
GUI: Graphical User Interface
HDD: Hard Disk Drive
HLCIT: High Level Commission for
Information & Technology
HMD: Head Mounted Display
HTML: Hypertext Markup Language
HTTP: Hyper Text Transfer Protocol
I/O: Input Output
IBM: International Business Machine
IC: Integrated Circuit
ICL: International Computers Limited
ICT: Information and Communication
Technology.
IMS: Information Management System
IPX: Internetwork Packet eXchange.
IRC: Internet Relay Chat
IRTB: Industrial Real Time Basic
IRTB: Industry Real Time Basic
ISA: Industry Standard Architecture
ISP: Internet Service Provider
IT: Information Technology
ITPDC: Information Technology Park
Development
ITPF: IT Professional Forum
JPEG: Joint Photographic Expert Group
KB: Kilo Bytes
Kbps: Kilobits per second
KIPA: Korean IT Industry Promotion Agency
LAN: Local Area Network
LCD: Liquid Crystal Display
LED: Light Emitting Diode
LISP: List Processing
LSI: Large Scale Integrator
MAN: Metropolitan Area Network
MB: Mega Bytes
MBPS: Million Bit Per Second
MBR: Master Boot Record
MCGA: Monochrome Display Adaptor
MD2D: Mini Disk Double Sided Double Density
MD2HD: Mini Disk Double Sided High Density
MD2HD: Mini Disk Double Sided High Density
MDA: Monochrome Display Adaptor
MF2D: Micro Floppy Double Sided Double
Density
MICR: Magnetic Ink Character Reader
MIDI: Musical Instrument Digital Interface
MILNET: Military Network
MIPS: Millionth of Instruction Per Second
MIS: Management Information System
MODEM: MODulator and DEModulator
MOEST: Ministry of Environment Science and
Technology
MOS: Metal Oxide Semiconductor
MPEG: Motion Picture Expert Group
MSAU: Multi Station Access Unit
MS-DOS: Microsoft Disk Operating System
MSI: Medium Scale Integration
NAV: Norton Anti Virus
NCC: National Computer Centre
NDD: Norton Disk Doctor
NEC: Nippon Electronics Company
NFS: Network File System
NITC: National Information Technology
Centre
NITCC: National Information Technology
Co-ordination Committee
NITDC: National Information Technology
Development Committee
NPC: National Planning Commission
NT: New Technology
NTFS: New Technology File System
OAS: Office Automation System
OCP: Order Code Processor
OCR: Optical Character Reader
OLE: Object Linking and Embedding
OMR: Optical Mark Reader (Recognition)
OS: Operating System
PC: Personal Computer
PCB: Printed Circuit Board
PCI: Peripheral Component Interconnect
PDF: Platform Independent Document Format
Pixel: Picture Element
PL/1: Programming Language -1
PM: Phase Modulation
PNG: Portable Network Graphics
POP: Post Office Protocol
POS: Point of Sales
POST: Power On Self Test
PROGLOG: Programming Logic
PROM: Programmable Read Only Memory
PS/2: Personal System-2
PSROM: Pseudo Random Access Memory
PSTN: Public Switched Telephone Network
QBE: Query By Example
QEL: Query Language
RAM: Random Access Memory
RDBMS: Relational Database Management
System.
RISC: Reduced Instruction Set Computer
RMM: Read Mostly Memory
ROM: Read Only Memory
RONAST: Royal Nepal Academy Of Science and
Technology
RPG: Report Program Generator
RPM: Rotation Per Minute / Revolution Per
Minute
SCP: System Control Processor
SCSI: Small Computer System Interface
SDRAM: Synchronous Dynamic Random Access
Memory
SIMM: Single In Line Memory Module
SMPS: Switch Mode Power Supply
SMTP: Simple Mail Transfer Protocol
SNOBOL: StriNg Oriented symBOlic Language
SPX: Sequenced Packet eXchange.
SQL: Structured Query Language
SRAM: Static Random Access Memory
SSSD: Single Sided Single Density
STP: Shielded Twisted Pair
SVGA: Super Video Graphics Array
TB: Terra Bytes
TCP/IP: Transmission Control Protocol/
Internet Protocol
TPS: Transaction Processing System
UNIVAC: Universal Automatic Computer
UPS: Uninterruptible Power Supply
URL: Uniform Resource Locator
USB: Universal Serial Bus
UTP: Unshielded Twisted Pair
VDT: Video Display Terminal
VDU: Visual Display Unit
VGA: Video Graphic Array
VLSI: Very Large Scale Integration
VoIP: Voice Over Internet Protocol
VR: Virtual Reality
VRML: Virtual Reality Modeling Language
VSAT: Very Small Aperture Terminal
W3C: World Wide Web Consortium
WAIS: Wide Area Information Server
WAN: Wide Area Network
WORM: Write Once Read Only Memory
WWW: World Wide Web
XMS: eXtended Memory
XT: eXtra Technology
Computer Network And Telecommunication
Data communication: The process of
transferring data or information between computers called data communications.
Telecommunication: It refer all types
of data transmission like characters, numerical, photos, audios and videos etc
using electronic or light emitting media.
Cables (Guided Media): Cables are the
most common transmission media. Two or more devices are connected directly
using cables. Three types of cables are used in computer networking they are:
Twisted pair cable: Twisted copper
cables are used only for lower bandwidth. It consists of two isolated strands
of copper wire twisted around each other. There are two types of twisted pair
cables they are as follows:
UTP (Unshielded Twisted Pair): UTP
cables does not have metal shield expect plastic coating. It contains number of
twisted pairs of wires with a simple plastic casing. It commonly used to for
LAN and Telephony. It is cheaper and easier to work with, but do not offer high
bandwidth and good protection from interferences. It can support data
transmission rates from 10 to 100 mbps.
STP (Shielded Twisted Pair): STP is
similar to UTP but it is shielded with metal sheath along with plastic coating.
It offers high bandwidth and good protection from interferences. It is cheaper
than fiber optic cable. It can support data transmission rates from 10 to 500
mbps.
Co- axial cable: A co-axial carries
higher bandwidth than twisted pair, it is easy to connect. It does not bend
readily. This cable consists of one or more small cables in a protective
covering. It offer very high data transfer rate and can be placed underground
and laid on the floors of lakes and oceans.
Fiber Optic cable: Fiber optic cable
is a thin filament of glass fiver wrapped in a protective jacket. It consists
of strands of glass like thread, each about the diameter of a human hair. It
offer high-speed data transmission rate because data travel as high-speed
pulses of light.
Wireless (Unguided Media): It is used to
transfer data with in a large geographical areas or globally without the use of
interconnecting wires or cables. It uses other components such as radio
signals, microwaves, or infrared to connect network.
Types of wireless communication:
Microwave Systems: Microwave signals
are similar to radio and television signals and are used to transmit data
through the space without the use of cable. It provides high-speed data
transmission. These signals cannot bend or pass obstacles like hills and tall
buildings, so very high towers are used to mount the signals. The transmission
is limited about 30 miles. Chain of towers is required to transmit the
microwave signals in a long distance
Satellite communication: Both
microwaves signals and telephone signals can be relayed to a earth station for
transmission to a communication satellite. The earth station consists of a
satellite dish that functions as an antenna a communication equipment to
transmit and receive data from satellite passing overhead. It is not disturbed
by hills and tall buildings and visible from any point. So sender and receiver
easily communicate with each other using antenna by aiming the satellite. It is
very expensive for placing satellite along the earth orbit.
Modulation: The process of changing
some characteristics (amplitude, frequency or phase) of carrier wave in
accordance with the intensity of the signal is known as modulation.
Types of modulation:
Amplitude Modulation (AM)
Frequency Modulation (FM)
Phase Modulation (PM)
Mode of communication:
Simplex mode: Simplex is one-way data
transmission that takes place only from sender to receiver. An example of
this would be a television that allows the signal to pass in only one
direction. Computer network connections do not use simplex.
Duplex mode: Duplex is two-way data
transmission that takes place both directions over a communication channel.
Computer use duplex channel. For example if computer A and computer B are
connected together than both computer can share data or information. From
computer A to computer B or computer B to computer A.
Types of Duplex Mode:
Half duplex: Half duplex is two way
data transmission that takes place in only one direction at a time eg walkie
talkie
Full duplex: Full duplex is two-way
data transmission that takes place in both directions at a time.
Computer Network: A computer network
is a logical or physical interconnection between two or more computers such
that they could communicate with each other. It is used to provide users with
the access to share resources. These shared resources include data files,
application software and hardware.
Components of computer network.
Computer Transmission
media Network software.
Protocols. Networking
cables.(Transmission media)
Advantages and disadvantages of computer
network.
Advantages of computer network:
Resources, data, software and hardware can
be shared.
Faster & cheaper communication and data
transmission.
Flexible working condition.
Office automation can be making very
effective well managed.
Disadvantages of computer network.
High installation and administrative cost.
Attack on the privacy of the people.
Computer virus spread most easily through
network.
If the server is out of order, then all
workstations are hang up.
Network architectures or (Types of Network
Architecture) or LAN Architecture:
Client server: This is old model of
computer network. In this kind of network model one main computer equipped with
very powerful processor, large memory and network operating system works as a
main computer or service provider. Other computers connected with server, which
are also called workstation or node or terminals can use the hardware and
software resources of server computer. There are different types of server such
as file server, print server, network server or email server.
Advantages of client server network:
It works with any size or physical layout
of LAN.
The network can be expanded to any size as
we wish.
It provide very high level security
It reduces software installation time and
cost to all computers.
Disadvantages of client server network:
It is very difficult to setup and well
trained technicians are required to handle and setup.
It is expensive compare to peer to peer
network.
All software and operating systems are
installed in server computer so that other client computer has to depend on it.
Peer to peer: It is also called
workgroups also. Because all computers in the network have equal
responsibilities. All computers in the network have access to at least one or
more computers. It mostly used in LAN and every organizations, research centers
such as banks, travel agencies, airlines educational institutions etc.
Advantages of peer to peer network:
It is easy to setup.
Users in each computer can determine the
resources to be shared among other computers.
Any required software can be installed on
individual computers , they don’t have to depend on the server.
It is cheaper compare to client server
network.
Disadvantages of peer to peer network:
It is slow because of heavy load.
It is suitable for limited area such as
school offices and small organization.
The network expansion is limited and can
not be expanded as the wish.
It has limited security level.
Types of computer network:
Local Area Network: The way of
connecting two or more computers in a very limited area (about 100 to 300
meters) or within a same building or a group of adjacent building is called
LAN. It enables very high speed communication through wire connection or
wireless connection some times. Small organizations prefer it because of less
expensive and faster communication.
Metropolitan Area Network: The way of
connecting computers inside a metropolitan area is called MAN. The area may be
a part of city, whole part of city, district, zone or country. Radio wave is
used to transmit the data for communication between the workstation and server
in the system. Many different systems of networking and computing are brought
together to form a MAN.
Wide Area Network: The connection of
computers of networks covering more distance or the world by the help of wave,
frequency and satellite is called WAN. Different types of LAN and MAN are
connected to form a WAN. It covers more area but it is slower than LAN and MAN.
Network Topology: Set of rules and
regulations, which are essential for networking are called topology. It may
contain software, hardware or geographical situation of the networking. Or in
another words it is the pattern in which the computers are interconnected.
Types of Network Topology:
BUS Topology.
Key Features
|
Advantages
|
Disadvantages
|
Uses a single length of cable to
interconnect network devices.
|
The failure of one computer does not
affect the performance of the rest network.
|
It tends to slow down under the heavy
load.
|
Uses terminators to dampen signal
reflection at the ends of the cables.
|
Computers can be easily added or removed
from the network.
|
Commonly uses coaxial cable, which is
prone to cable breaks. This will disrupt network use.
|
Network devices connect directly to the
cable.
|
Less physical cable is required to make
the network. So it is cheaper and easy to implement.
|
If a cable break or problems occur, the
entire network goes down.
|
Ring Topology:
Key Features
|
Advantages
|
Disadvantages
|
Devices are connected in a ring
formation.
|
1. Each computer does not have to depend
on the central computer as each computer controls transmission to and form it
self.
|
1. If a single computer fails, at least a
portion of the network will not work.2. It is difficult to change the network
structure.
|
A star ring uses an MSAU (Multi-station
Access Unit) to form the ring function internally.
|
2. Devices in a star ring configuration
can be added and removed without network disruption.3. It has short cable
connection, which increases the network reliability.
4. It support very high data transmission
rate
|
3. The MSAU in a star ring provides a
single point of failure.4. An extensive rewriting must be done to maintain
the ring structure when computers are added or removed.
|
Star Topology:
Key Features
|
Advantages
|
Disadvantages
|
Most commonly implemented network
topology used today.
|
1. Computer systems can be added or removed
from the network without disrupting network users.
|
1. If centralized device (hub/switch)
fails whole network goes down.
|
Uses individual cables to connect each
device to the network.
|
2. A cable failure affects only the
network device connected to it.
|
2. Because each device requires its own
length of cable, more cable is required than in a bus topology.
|
Problem isolation is straight forward.
|
3. When a device fails in a star
topology, it can be easier to trace the location of the problem.4. It support
very data transmission rate.
5. It is more reliable
|
3. Additional network equipment such as
the hub or switch is needed to make the network connection. So it is
costly.4. It is difficult to expand.
|
Different devices and terms used in
Network:
MODEM: Modem is a device that directly
converts digital signal from a computer or other digital devices into analog
form for transmission over analog link i.e telephone line and vice versa. MODEM
stands for Modulation and Demodulation. There are two types of modem used in
computer they are as follows:
Internal modem . External modem.
NIC: It is a Network Interface Card,
which connects each computer to the wiring to the network. A NIC is a circuit
board that fits in one of the computer’s expansion slots. It provides a port on
the back of the computer to connect in the network.
Hub: Hubs are connectivity devices,
which contain multiple ports for connecting to network components. Hubs connect
the computers in a star topology. It lies between server and clients computers.
Connector : Bridge and Gateway are the
two different connectors, which play role to link between two network systems.
Bridge: Bridge connects networks using same
communications protocols or similar networks so that information can be passed
from one to the other.
Gateway: Gateway connects networks using
different communications protocols or dissimilar networks so that information
can be passed from one to the other.
Switch: A device that capable of
forwarding packets directly to the ports associated with particular network
addresses. Hubs and switches are almost same but switch is new technology
and intelligent compare to hub.
Repeater: A device used on
communications circuits that decrees distortion by amplifying or regenerating a
signals so that it can be transmitted onward in its original strength and form
as they pass through a network cable.
Protocols: Protocols are the set of rules
and formats for sending and receiving data. It works as guidelines to govern
the exchange between equipments. There are different types of protocols
that we can use. Some of popular protocols are TCP/IP, HTTP, FTP, IPX/SPX.
Router: A router is a device that is
used to connect different LAN in the network. It receives transmitted messages
and forwards them their correct destinations over most efficient available
route.
NOS: The operating, which can support
network environment, is called Network Operating System. For example Windows
XP, 2000, server, unix, linux, Novel Netware etc.
Band
width : The amount of data that which is sent through a
data-transmitting medium, such as a computer network, telephone line, or
coaxial cable, in a given amount of time is called band width.
Bits : In computer processing and
storage, a bit is the smallest unit of information handled by a computer and is
represented physically by an element such as a single pulse sent through a
circuit or a small spot on a magnetic disk capable of storing either a 1 or a
0.
Multimedia Multimedia : The
technology of combining speech, hypertext, text, still graphics, animation,
moving pictures and sound using the computing power of PC is known as
multimedia.
. Multimedia has become a prerequisite for
computer games of all kinds. Its use is growing in computer based education
(CBE) and computer based tanning (CBT). Some of them are categorized as
follows:. Graphics Interchange Format (GIF). Joint Photographic Expert Group
(JPEG). Protable Network Graphics (PNG). Motion Picture Experts Group (MPEG-2)
. Musical instrument digital interface (MIDI) IT Policy Of Nepal 2002 A.D
(Suchana Prabidhi Niti 2057 B.S) The information technology (IT) policy, Nepal
was adopted in 2002 A.D i.e 2057 to define the visions, background, objectives
and strategies of computer education in Nepal. Below, we briefly discuss the
important ones:
Vision: “To place Nepal on Global Map of
Information Technology within next five years,” is the main vision of IT policy
of Nepal 2002.
Objectives /Purposes of the IT policy 2002
of Nepal are as follows:
To create knowledge based society
To create job opportunities for the people.
To establish knowledge based industries.
Main polices of IT policy of Nepal To flow the information after the
development of web site of all ministries and departments of government.
To develop E-commerce
To develop E-education
To develop E-health
Work policies of IT policy of Nepal
To develop the communication system if
local areas
To develop the needed and ablest manpower
in local areas
To develop the communication system
globally
Strategies if IT policy 2002:
Legalize and promote e-commerce by using
information technology.
Utilize information technology in the
development of rural areas.
Include computer education in curriculum
from the school level.
Increase export of services related to
information technology.
IT policy: some of the policies to be
followed for the implementation of the above mentioned strategies are as
follows:
To declare information technology sectors
as a prioritized sector.
To provide internet facilities to all
village development committees of the country.
To computerize the records of each
government office and build websites for them.
To increase the use of computers in the
private sector.
Action Plan: These are some action
plan to fulfill the objectives of IT policy.
Participation of private sector in
infrastructure development.
Infrastructure development.
Human Resource Development.
Promotion of E-Commerce.
Legal provisions: Government of Nepal
will design, update and implement the cyber laws from time to time as per
national international situation. The law will be related to e-banking, digital
signature, software piracy, data protection by encryption copyright protection
and privacy protection act, etc
NITCC: NITCC stands for National
Information Technology Co-ordination Committee; its main purpose is to assist
the development of IT in our country. Main functions of NITCC are as follows:It
provides the text books of National Communication System
It increases the status of people
It develops the man power and intentional
works
NITC: NITC stands for National
Information Technology centre. It is also governmental body to work for the
development of IT in our country. It is established to develop the field of
information system, to re-observe, to know yearly development and to solve the
problems. It is form by twelve members including science and technology
minister as president.
NITDC: It stands for National
Information Technology Development Committee. It is form by eighteen members,
where prime minister work as president and science and technology minister work
as vice-president.
Cyber Laws, Ethics and Policies of Nepal.
Computer crime: Computer crime is a crime
committed by the people through the use of computers.
Example of computer crime:
Unauthorized access of computer
Altering web pages of web site.
Denial of Service (DoS) attacks.
Malicious computer programs: viruses,
hacking and cracking the software.
Effects of cyber / computer crime.
Physical theft of computer and computer
accessories which cause a huge damage of the assets.
Due to the attackers, the banks and
financial companies get adverse publicity.
Vandalize the original web page with the
different contents in WWW.
Lost of privacy due to the unauthorized
access of information.
Safety from computer crime:
Protection of computer from power related
problems by using power surges and power outrages.
Using call back systems to track the phone
number which is used to connect.
Using firewall system to protect computer
from external threats.
Using computer to protect from viruses.
Making backup regularly.
Computer related legal problems:
Plagiarism: The presentation of
somebody’s work as if it were your own is known as plagiarism. For example some
people or students copy the material from the internet and present them as if
it is their own creation without prior permission from the authorized person to
copy from the copyrighted material.
Software Piracy: Copying software CD
or DVD is another big problem. People copy software and install in their
computer. Some programs are freely available in the public domain under the
provision of General Public License (GPL).
Digital signature: A security
mechanism used on the internet that relies on tow keys, one public and one
private, which are used to encrypt and to decrypt them on the receipt.
Public key infrastructure (PKI): PKI
is a security management system including hardware, software, people, processes
and policies, dedicated to the management of Digital Certificates (keys) for
the purposes of secure exchange of electronic messages.
Private Key: One of the two keys in
digital signature’s public key encryption. The user keeps the private key
secret and uses it to encrypt digital signatures and to decrypt received
messages.
Public key: One of the two keys in
public key encryption. The user releases this key to the public, who can use it
for encrypting messages to be sent the user and for decrypting the user’s
digital signature.
Cyber law : The law which is practiced
to control The following three basic types of computer crimes such
as: theft of computer time for development of software, theft, destruction
or manipulation of programs or data and alteration of data stored in the
computer file is called cyber law. Cyber law is the legal field that
maintains the order of track in the internet access and communication.
The scopes that are covered by boundary of
cyber law are as follows:
Intellectual property: Computer crime law
Jurisdiction law Digital signatures system
Privacy Freedom
of expression.
International cyber law: Now a day’s
several cyber laws are applied to provide all types of computer security,
software security and avoid computer crimes. Some famous and cyber laws are as
follows.
Fair Credit Reporting Act in 1970- free
access of personal credit report.
Freedom of Information Act in 1970- access
of information posted by the government.
Federal Privacy Act in 1974- access right
of government to see any record.
Video Privacy Protection Act in 1988-
prohibition of personal record without judiciary order.
Copyright Act 1992- Unauthorized copy of
software. (5 years Jail or US$ 25,000 or both)
Computer Matching and Privacy - right
of government to keep the personal key record
Computer Ethics: Computer Ethics
covers all the practical principles that deal with how the computer experts
should make decisions in regard to the social and professional behavior. The
term ‘computer ethics’ first devised by Mr. Walter Maner in mid 70s. But it is
practiced from the beginning of 90s.
The
core issues of computer ethics incorporate:
Technological impact on the society. Intellectual property rights
Copyrights Piracy
Hacking Internet
pornography and adult sites
Computer ethics for the computer user:
Respect yourself and do not give passwords
to any second person.
Do not ask password and never try to know
other’s password for any purpose.
Always give the credit to your originality.
Ten Commandments for computer ethics: The
computer Ethics Institute of the Brookings Institute, Washington D.C has
developed the following ethics:
Thou shalt no use a computer to harm other
people.
Thou shalt not interfere with other
people’s computer work.
Thou shalt not to use a computer to bear
false witness.
Thou shalt not to copy or use proprietary
software for which you have not paid.
Computer Ethics for computer
professionals: The codes of conduct and good practice for certified
computer professionals are the essential elements of activity. They are:
A high standard of skill and knowledge.
A confidential relationship with people
served.
Public reliance upon the standards of
conduct in established practice.
The observance of an ethical code.
:Association for Computing
Machinery (ACM) codes of ethics is four point standards that govern the
ethical behavior among the computer professionals.
Uniform Computer Information Transaction
Act (UCITA) defines a set of standards related to the legal ethical behavior
during the computer contract process.
Computer security:
In the 21 st century computer is most
important part of our life.Like other asset’s security computer security is
very important.The protection of computer, its accessories, data and programs
for a long lasting of computer system is known as computer security.
Computer security is classified into two
parts:
Hardware security
The
protection of all hardware components used in computer system is known as
hardware security. For the proper management of physical security of the
computer, we have to maintain
Regular maintenance Computers are delicate
machines. They need regular maintenance, cleaning, and configuring new hardware
removal of unnecessary hardware.
Insurance Insurance is a very good method
to protect other assets. Computer insurance helps us to insure our computer, if
we lost it or parts are damaged or in case of calamities of theft loss of data.
Free of dust Computer parts are very
sensitive to dust. Dust can damage internal and external both parts of computer
so to protect from dust we must put computer in very neat and dust free room.
And we should use dust cover also to protect computer.
Air condition system Most of the electronic
device gets damage in excessive heat. So room must be cool and dust free for
computer. If there is excessive heat then computer parts may not work properly
or it may stop functioning. It is suggested to maintain temperature between 18
o to 24 o Celsius and relative humidity of 50 to 60 percent. Micro computers
can work up to maximum 30 oC also. But today’s new personal computers are
designed to work even between 0 oC to 40 oC.
Power supply Power supply is another cause
of damage of computers. Computer needs 220V to 240V AC constantly. The voltage
fluctuation may damage integrated circuits of computers chips because these are
the most sensitive parts of computers. To protect from voltage fluctuation we
must use UPS to protect our computers from sudden interruption of power because
in such cases UPS provide power for some minutes to hours from backup battery
inside it. Volt guard and Spike guards and Stabilizers are common device used
in these days.
Software security
The software is very important part of the
computer. It includes programs and data or information store in
computer. The protection of data and programs used in computer system is
known as software security. Software security is required for the,
Prevention of loss of data,
Prevention of data and software program
piracy
Prevention of corruption of data and
Prevention from error reading of data.
Some
common software security measures are as follows:
Password protection Password is a set of
characters that act like a key to unlock the system and other files and
programs. Setting password in our files and user account to control the access
of data and information in our computer is very good and effective method of
software security. Password must be difficult to guess so we should not use common
words as password. It is suggested to use the set of numbers, symbols and
characters to create password.
Some common rules to create password:
Password length must be at least 6
characters.
The words used to set password must be
difficult to guess
We should keep our password confidential
We must change password frequently
Backup system If data and information is
very important. We must backup data regularly to other computer or other disk
location and folders of the same computer so that we can restore it if data is
corrupted or lost.
Data encryption and decryption We can
prevent the access of data or information by encrypting it. Windows operating
system have built in feature to encrypt the data. If we encrypt the data
computer will change the forms of this data and will not be readable or
understood to other users. And if we have to give access we can decrypt it into
original form.
Defragmentation Defragmentation is the
process of a file to contiguous sectors on a hard disk to increase the speed of
access and retrieval. Because during long time files and folders store in
computer will get fragmented or will be unmanageable in such case disk head
will consume more time to read the data from the disk means computers becomes
slower. So it is necessary to defragment the disk to increase the performance
of the computer.
Firewall protection Windows firewall is
very important and useful tool to protect our computer from external and
internal threat in LAN and Internet. While downloading files and programs form
internet viruses and other person may try to access the resources of our
computer. In such case windows firewall block such threats.
Scanning disk Computer store all
information in its disk surface. And hard disk is a main part where computer
store all its information. So we must scan the surface of the to increase the
performance of the computer. Windows provide some built in tools to scan the
disk such as Scandisk and CHKDSK and several other utilities software are
available to scan disk.
The Internet and E-mail:-
Internet: The internet is worldwide
collection of computer networks and gateways that use TCP/IP suite of protocols
to communicate with one another using telephone lines modems or satellites.
Internet is network of networks. At the heart of the internet is a backbone of
high speed data communication lines between major nodes or host computers,
consisting of thousands of commercial governmental, educational and other
computer system, that route data and messages.
Some of the common services provided by the
internet are:
Electronic mail (E-Mail) Information sharing and
resources. Business communication Advertising Online shopping
Stock trading Discussion and chat Entertainment E-banking Equipment
used in internet/ components required to use internet:
A set of computer
A modem and regular telephone line or
broadband internet connection.
An account in ISP to access the internet
host.
A communication software for example:
Internet Explorer, Netscape Navigator, Mozilla Firefox or Opera etc.
Terms related to the internet:
WWW: WWW is a series of services that
are interconnected through hypertext. It provides link in the web documents.
Advantages of www:
A link in a web document can be used to
open other documents.
Web pages can contain pictures, buttons and
even links to sound files in addition to text, thus allowing multimedia
applications.
Sophisticated web document allow users to
interact with applications through dialog boxes and forms.
Web site: Website is a location of the
web pages created by any organizations, universities and government agencies to
provide information regarding them like: http://www.bbc.co.uk/nepali,http://www.nepalnews.com etc. Each
website has its own address that is also called internet address.
Web pages: Webpage is a collection of
information that is stored in website. The www consists of huge collection of
documents with related website called webpage. Webpage provides vast collection
of information of related websites.
Browser: Browser is client software
that allows the users to display and interact with the web page. For example:
Internet Explorer, Netscape Navigator, Mozilla Firefox or Opera etc.
Web server: web server is a site on
which the web pages are kept. It is a server computer that responds to requests
from web browsers to relative resources.
Domain name: It is a name of specific
internet area controlled by any organization, company or government.
Home page: The home page is the first
hypertext document regarding the web address displayed when a user connects to
any web server.
ISP( Internet Service Provider) A
company that provides individuals or companies access to the internet and the
world wide web is called ISP.
Firewall: software or hardware that
limits the certain kinds of access to a computer from the internal network or
external network.
E-Mail: E-mail stands for electronic
mail. It is most widely used feature on the internet. Sending and
receiving messages electronically through the internet is called
E-mail. We can exchange any message with the people around the world by
using e-mail.. We can write an e-mail message in an mail program like Eudora,
Outlook Express, Netscape Navigator etc. and several web base program like
Yahoomail, Hotmail, Gmail and Zapakmail are also used to send and receive
e-mail.
E-mail address: Each E-mail address is
identified by a unique name is called E-mail address. For example shiva@yahoo.com, ram@fewanet.com.np, etc. It has five parts
they are as follows:
Ram : User’s name
@ (At the rate) : A separator symbol
Yahoo, fewanet : ISP address or domain name
.com or .edu or .net : commercial or
educational groups
.np : Country code
Advantages of using E-mail: It is cheapest
and fastest means of communication and as compared our conventional postal
mail.
It is more reliable than postal mail.
E-mail can be accessed from any part of the
world and at any time.
A single mail can be send to multiple
people at a time.
E-fax: E-fax stands for electronic fax. It
is very powerful desktop application that allows us to send and receive faxes
directly on our computer. It is very similar to e-mail. The E-fax first goes to
the internet server then the internet server sends it to its destination
whereas E-mail means first goes to the local file server.
Different between E-mail and E-fax:
E-mail
|
E-fax
|
1. It is very cheap.
|
1. It takes more cost than E-mail.
|
2. Message first goes to the local
server.
|
2. Message first goes to the internet
server and then to its destination.
|
Computer Virus Definition: A computer
program that can replicate itself by making copies itself without the user’s
knowledge is called virus. Virus can destroys the data files, program files and
system files of the computer.
Purposes of creating virus.
To protect software from software piracy.
To sell anti-virus program and earn money.
To entertain the user by generating
pictures and interesting messages on the screen.
For the criminal purposes such as to hack
server computer of very sensitive organization or government offices.
Symptoms of computer virus. (What a virus
can do to computer?)
Computer becomes slow by reducing memory space.
Computer may not boot and hang quickly.
System files may corrupt and affect the
performance of computer.
Date and time change automatically.
Antivirus Software:The programs which can
detect and eliminate the computer viruses are called anti-virus software. For
example Norton, Panda, F-port, Pe-cilin, AVG, Avast, Nod32, Avira, MacAfee,
Smart Dog, Kaspersky, Sophas etc.
Prevention and protection from virus:
Install reputed anti-virus software and use
regularly.
Never install pirated software.
Do not open e-mail attachment and e-mail
from unknown person before scanning at first.
We must make backup copy of valuable data
so it can be restored from original location in case of damage.
Types of computer
virus:There are many categories of viruses, including parasitic
or file viruses, bootstrap-sector, program virus or file virus multipartite,
macro, stealth virus and script viruses.
Bootstrap-sector
virus:Bootstrap-sector viruses reside on the first portion of the hard
disk or floppy disk, known as the boot sector or Master Boot Record (MBR).
These viruses replace either the programs that store information about the
disk’s contents or the programs that start the computer. Typically, these
viruses spread by means of the physical exchange of floppy disks. These viruses
are also called as start-up infector virus. Examples of such viruses are Danish
Boot, Devel 941, Disk killer etc.
Multipartite viruses:Multipartite
viruses combine the abilities of the parasitic and the bootstrap-sector
viruses, and so are able to infect either files or boot sectors. These types of
viruses can spread if a computer user boots from an infected diskette or
accesses infected files. Examples of such viruses are Invader, Flip, Tequila,
etc.
Parasitic or file viruses or
program files:Parasitic or file viruses infect executable files
or programs in the computer. These files are often identified by the extension
.exe , .bin, .sys, .drv etc. in the name of the computer file. File viruses
leave the contents of the host program unchanged but attach to the host in such
a way that the virus code is run first. Then it will affect execution of the
program and hence the computer becomes very slow. Examples of such viruses are
Acid Rain, Alien 298, Crazy, Brontok Script viruses: Script viruses are written
in script programming languages, such as VBScript (Visual Basic Script) and
JavaScript. These script languages can be seen as a special kind of macro
language and are even more powerful because most are closely related to the
operating system environment. The ‘ILOVEYOU’ virus, which appeared in 2000 and
infected an estimated 1 in 5 personal computers, is a famous example of a
script virus.
Macro viruses: Macro virus contains inside files. Macro command which is designed
to infect a specific type of document files such as Ms Word or Ms. Excel files.
Examples of such viruses are DMV, Nuclear and Word Concept.
Stealth viruses: Stealth virus is one of the most dangerous types of
viruses which really give information about the presence of it in the computer.
Generally it infects the boot sector records and program files. It is difficult
to detect using anti-virus program because it can hide in memory from the
operating system and antivirus software. Some time they can hide other files.
Examples of stealth virus are Frodo, Joshi, Whale, etc.
Microsoft Access
Introduction to Database System : In
our daily life we encounter with various software. There is hardly any software
that does not use database systems.
Data are information to the computer which
are processed to get desired result and are the piece of information.
Information: The data which gives
meaning or suitably arranged for communicating interpretation, and processed by
human being by automated means such as computer is called information.
Database: A database is a collection
of data that is organized so that its contents can easily be accessed, managed
and updated.
File: A file is a collection of
electronic information store in computer.
Record: A record is a information
about an element such as a person, animal, students, place etc.
Filed: A filed is a piece of
information about an animal, person, students, place etc. And these fields are
the titles in the table of Ms-Access.
DBMS: A database management system
(DBMS) is a computer program designed to manage a database (a large set of
data), and run operations on the data requested by clients. For example Oracle,
Microsoft Access, Ms. SQl, MySQl, dBASEIII+, dBaseIV, FoxPro, IMS, IDS, IDMS,
ADABASE, CDS/ISIS, OMNIS, RBASE, SYSBASE, FOXBASE etc. are the well known
database management system.
RDBMS: Relational Database Management
System (RDBMS) is method of viewing information from several, separate database
that relate to one another through the keyword or values. The main advantage of
RDBMS is that we can simultaneously use more than one database to see
information stored in them.
Importance of database:
Database stores the data.
Computerized database saves data from being
lost.
Computerized database protects from
unauthorized access and use of the data.
Data can be stored in a small area or space
in computerized database.
Features of DBMS:
Easy to access data. Ease to modify data.
Delete existing data. Linking between two
or more databases.
It can be used as SQl (Structured Query
Language)
Microsoft Access is very powerful and most
popular desktop database management system where we can create and maintain
related data. It comes in a office package with other software such as Ms.
Word, Excel, Power point etc. It is a relational database management system
(RDBMS). In multi-user environment it supports file and data sharing mechanism.
Microsoft Access is a fully functional RDBMS. It provides all the data
definition, data manipulation, and data control features you need to manage
large volumes of data. .
Features of Microsoft Access:
It provides very useful database features
such as tables, forms, reports and queries.
This provides end-user applications
developer environment.
It shares data with other application such
as Microsoft Word or Excel.
It support three computer programming
language such as: SQL, Macros and Visual BASIC etc.
SQL: SQl stands for Structured Query
Language. It is a tool that allows the database. It enables the users to
extract, manipulate and related to learn data from one or more tables.
Macros: It is a list of actions which
can be executed by clicking specific button is called macros.
Visual BASIC: It is very advanced and
flexible and comprehensive language you can uses to dev lop complete user
interactive applications.
Typical Uses for Microsoft Access
Here are just a few of the ways Access can
fulfill the needs of a wide range of users.
Small Business Consulting Sales
and Marketing
Large Corporation Personal Use
Parts of Ms. Access
Table: A table is collection of data
about a specific topic, such as products or suppliers. Using a separate table
for each topic means that you store that data only once, which makes your
database more efficient, and reduces data entry errors.Table is the primary
object of Ms Access. A table stores data in tabular form. A table is made up of
rows and columns. Some parts of table are as follows:
Fields (column): The title name of the
column that holds data is known as field. A table can have many fields.
Records (rows): The collection of data
horizontally for each field is known as record. A record is complete
information about an entity.
Data: The actual information stored
under a filed title in a row is called data.
Index: A table can have index attached
with it. The index is used to keep the data in organized for and helps faster
retrieval of data.
Primary key: A primary key is a field
which is uniquely identified. All the records of a table are uniquely
identified on the basis of primary key. The column that has been defined as the
primary key can’t hold null value. For example a student’s roll no. can be
defined as primary i.e can’t be null and repeat.
Compound key: The primary key based on
more than one field is known as composite key. It consists of multiple columns,
because one column is not sufficiently unique.
Foreign key: Foreign key is the
linking pin between two tables. It shows the relation between any two tables.
Queries: a query is search or question
that you make for a record or item. The record is stored in the database file.
Queries help to investigate about data records.
Forms: Forms present the data from a
table or a query in a way we want it to be displayed. The fields in the table
or query are made available to place on the forms we create. Use of form.
Displaying and editing data. Controlling application flow.
Accepting input. Displaying messages. Printing information.
Reports: Reports are the printed
results of data processing. Reports are specially formatted collections of
data, organized according to your specification for summarizing and printing
listings of database data. While forms are designed to be used onscreen,
reports are designed to be viewed and printed.
Relationship: In a database we can
establish relation between any two or more tables. Because no data are
isolated, but they are associated or related with each other entity in one or
another ways. we can generate reports and manipulate data using such
relationship between tables.
Types of relationship:
Many to many relationship: A many to
many relation is unclear. Many to many relations often are a sign that further
analysis is required.
Many to one relationship: Many to one
relation is the same as one to many, but from a different view point. Using
this relation two or more fields of one table can be link with one field of
another table.
One to many relationship: Most
relation in tables are one to many, means one field of a table can be link with
two or more fields of the another table.
One to one relationship: A one to one
relation exception in database. It can be established using primary key and
foreign key in the DBMS.
Details of Data Type of MS. Access
Data type defines the nature of the data to
be stored in the column. Access provided different types if data that can be
stored.
Text : (Default) Test or combination
of text and numbers, up to 255 characters.
Memo : Use for lengthy text and
numbers, such as notes or descriptions. Stores up to 65,536 characters.
Number:Use for data to be included in
mathematical calculations.
Date/Time:Use for dates and
times Currency :Use for currency values and to prevent rounding off
during calculations..
AutoNumber :Use for unique sequential
(incrementing by 1) or random numbers that are automatically inserted when a
record is added.
Yes/No :Use for data that can be only one
of two possible values, such as Yes/No, True/False, On/Off. Nullvalues are not
allowed.
OLE Object :Use for OLE objects (such as
Microsoft Word documents, Microsoft Excel spreadsheets, pictures, sounds, or
other binary data) that were created in other programs using the OLE protocol.
Hyperlink : Text or combination of
text and numbers stored as a text and used as a hyperlink.
Lookup Wizard Use to create a field
that allows you to choose a value from another table or from a list of values
using a combo box— -choosing this option in the data type list starts a
wizard to define this for you.
Field Properties: Field size property is
set to the maximum size for data stored in the field set to the text or number
data type. For next data, the default field size is 50 and maximum size is
depending on the type of data types.
Format: It allows choosing different
format of data type available.
Decimal places: It is valid for only
numeric data and currency data, where the decimal places numbers vary fro 0 to
15.
Caption: It used to display
alternative name for the field to make the field name more explanatory. It can
contain up to 2,048 characters.
Default Value: Default value is the
one that enter automatically in the database and can be changed as per
required.
Validation Rule: It is used to set the
limitation while entering data in the database. It helps us to customize the
data entry and checks for error entry of data.
Validation Text: If wrong data is
entered which do not supported by given validation rule, it is used to display messages
on the screen and work as a precaution of wrong data entry.
Required: If required is set as Yes
then field should always receive a value during data entry.
Indexed: You can choose whether you
want to index the table. The available index options are unique index and
duplicate index.
Input Mask: It is usually used to set
control the data entry in the database. Using this option we can customize the
data entry by setting special commands using the following symbols:
Bottom of Form
Computer language:
Programming: The method used to develop a
solution or a program is called programming. It is way of writing program using
specific computer language to perform specific task.
Computer Language : The set of codes
which is used to write computer program is called computer language . It is
artificial language and can be used to define a sequence of instructions that
can ultimately be processed and executed by the computer.
Types of computer language. :
Machine level language: The program
written using machine code or binary numbers (0 and 1) is called machine level
language. It is computer’s own binary-based language, or machine
language, is difficult for human beings to use. It is machine dependent
complicated and time consuming. It is also called first generation language.
Low level language (Assembly
language) : The language which permits the use of mnemonics (which are
combination of codes and English phrases) for each instruction that machine can
do is called low level language. It remains in between machine level language
and high level language. Example pseudo programming.
High level language : The language
which uses plain English words or phrases and mathematical notation, following
the correct syntax (Certain rules which are followed to write programs) is
called high level language. It should be translated into machine code using
compiler or interpreter. It is also called third generation language. Example:
QBASIC, C, C++, LOGO, LISP, ADA, PASCAL etc.
Language processor : The set of
program codes, which are used to translate program written in high level
language or low level language into machine code, is called language processor.
There are three types of language processor.
Interpreter : The language processor
which converts High level language and Low level language into machine code is
called interpreter. It translates programming codes line by line so it is
slower than compilers and assemblers.
Compiler : The language processor
which translates the program written in high level language into machine code
is called compiler.
Assembler : The language processor
which translates the program written in low level language into machine code is
called assembler.
Source program : The original program
written in high level language is called source program. It should be
translated into machine code, so that computer understands and responses it.
Object Program : The program converted
into machine code by compiler is called object program.
Advantages of high level language:
It is very simple because plain English
words are used for programming.
There are pre-defined commands, which
minimize the work of programmers.
Features of high level language:
It is machine independent and problems
oriented.
It does not require extensive mathematics
knowledge and computer hardware knowledge.
Advantages of low level language:
The computation time of an assembly
language program is less.
Program debugging is easier.
Disadvantages of low level language :
I) It is machine dependent.
II) Too difficult to learn and implement.
Bug and Debug : Any type of error in
the program is called bug. The process of correcting bugs is called debug.
Introductions to C
C is a programming language developed
at AT & T’s (American Telegraph and Telephone) Bell Laboratories of USA in
1972. It was designed and written by a man Structured program: Structured
Programming, in computer science, a general term referring to programming that
produces programs with clean flow, clear design, and a degree of modularity or
hierarchical structure. Benefits of structured programming include ease of
maintenance and ease of readability by other programmers.
Advantages of C language: or Advantages of
structured program:
Modules and functions once built here can
be used in other programs.
It reduced testing and debugging time.
The program can be easily modified.
Characteristics / Features of C:
It is structured programming language.
It is general purpose programming language.
It contains rich and powerful set of
operators.
Various characters set in C language:
Alphabets A, B, ….., Y, Z, a, b, ……, y, z Digits 0, 1, 2, 3, 4, 5, 6, 7,
8, 9Special symbols ~ ‘ ! @ # % ^ & * ( ) _ – + = | \ { } , [ ] : ; ”
‘ < > , . ? /
What is ANSI?ANSI, in computer science,
acronym for the American National Standards Institute, an organization of
American industry and business groups dedicated to the development of trade and
communication standards; internationally, the American representative to the
International Organization for Standardization.
Variable : A entity whose value
keeps on changing during the program execution is called
variable. A variable is a name assigned to a data storage
location. Program uses variables to store various kinds of data during program
execution. In C, a variable must be defined before it can be used.
Rules for Constructing Variable Names
The first character in the variable name
must be an alphabet or underscore.
No commas or blanks are allowed within a
variable name.
No special symbol other than an underscore
(as in gross_sal) can be used in a variable name.
Keywords: Keywords are the words whose
meaning has already been explained to the C compiler (or in a broad sense to
the computer). Keywords are also called as reserved word.
Constant:A constant is a fixed entity.
It does not change its value during the entre execution.Types of constant:
Integer constants Floating point constants
Character constants String literals.
Operator: An operator is a
symbol that instructs C to perform some operation, or action, on one or more
operands. An operand is something that an operator acts on. In C, all
operands are expressions. C operators fall into several categories:
The assignment operator Mathematical operators
Relational operators Logical operators
The Assignment
Operator: The assignment operator is the equal sign (=). Its use
in programming is somewhat different from its use in regular math.
Unary Mathematical
Operators: The unary mathematical operators are so named because
they take a single operand where as binary takes two operands.
C’s unary mathematical operators.
Operator
|
Symbol
|
Action
|
Examples
|
Increment
|
++
|
Increments the operand by one
|
++x, x++
|
Decrement
|
–
|
Decrements the operand by one
|
–x, x–
|
The increment and decrement
operators can be used only with variables, not with constants. The operation
performed is to add one to or subtract one from the operand. In other words,
the statements. This type of operator are extensively used with looping control
statement such as for, while, do etc.
C’s binary mathematical operators.
Operator
|
Symbol
|
Action
|
Example
|
Addition
|
+
|
Adds two operands
|
x + y
|
Subtraction
|
-
|
Subtracts the second operand from the
first operand
|
x – y
|
Multiplication
|
*
|
Multiplies two operands
|
x * y
|
Division
|
/
|
Divides the first operand by the second
operand
|
x / y
|
Modulus
|
%
|
Gives the remainder when the first
operand is divided by the second operand
|
x % y
|
Relational Operators: C’s relational
operators are used to compare expressions, asking questions such as, “Is x
greater than 100?” or “Is y equal to 0?” An expression containing a relational
operator evaluates to either true (1) or false (0).
C’s relational operators.
Operator
|
Symbol
|
Question Asked
|
Example
|
Less than
|
<
|
Is operand 1 less than operand 2?
|
x < y
|
Greater than or equal to
|
>=
|
Is operand 1 greater than or equal to
operand 2?
|
x >= y
|
Less than or equal to
|
<=
|
Is operand 1 less than or equal to
operand 2?
|
x <= y
|
Not equal
|
!=
|
Is operand 1 not equal to operand 2?
|
x != y
|
Logical Operators: Sometimes you might
need to ask more than one relational question at once. For example, “If it’s
7:00 a.m. and a weekday and not my vacation, ring the alarm.” C’s logical
operators let you combine two or more relational expressions into a single
expression that evaluates to either true or false. Table given below lists C’s
three logical operators.
C’s logical operators.
Operator
|
Symbol
|
Example
|
AND
|
&&
|
exp1 && exp2
|
OR
|
||
|
exp1 || exp2
|
NOT
|
!
|
!exp1
|
Branching: Branching is based on
decision making. If the decision satisfied, then it can perform the task,
otherwise it executes the line next to it.
For example:If ……….. else If ……….. else if ………..else Switch case
Looping: looping is a process which
allows the data to be repeated unless or until some condition has been
satisfied. The various statements are:For
While Do while
Comments : Comments are the statements
that are used for user aid or remarks. The statements which are defined as
comments are ignored by C compiler comments are non-executable statements.
Comments are defined as /*…………your words…………..*/
Escape sequence : The set of characters,
which are not printed when used but provide various functions. Such escapes are
start with ‘\’ back slash. For example
Character Escape Sequence Bell (alert) \a Backspace \b
Identifiers: Identifiers are the name
givne to various program elements such as variables, functions or arrays. It
may consist both letter and digit but initial character must me letter and
maximum 31 characters can be used to name the identifiers. For example:
tax_rate, tax_year, year-2065 etc.
Library Functions: Various types of built
functions which can be used to execute different types of task such as
mathematical calculation, graphics management, memory management, data and file
handling etc.
Your First C Program
#include <stdio.h>
{
main()
printf(“Hello, World!\n”);
return
0;
|
}
- Find output -List real & formal parameters
- List user defined function, operators with
types
- What will happen if c=c+1 is removed in
Q.no. 1& 3.
- What will happen if N>0 is replaced by N<0 in Q. no. 2
- List user defined function, operators with
types
- What will happen if c=c+1 is removed in
Q.no. 1& 3.
- What will happen if N>0 is replaced by N<0 in Q. no. 2
- Re-write Q.no. 5 & 5 using
While….Wend
- Re-write Q.no. 3 using DO UNTIL….LOOP
1) DECLARE SUB RESULT()
CALL RESULT
END
SUB RESULT
N=5
C=1
WHILE C<=5
PRINT N
N = N * 10 + 5
C = C + 1
WEND
END SUB
- Re-write Q.no. 3 using DO UNTIL….LOOP
1) DECLARE SUB RESULT()
CALL RESULT
END
SUB RESULT
N=5
C=1
WHILE C<=5
PRINT N
N = N * 10 + 5
C = C + 1
WEND
END SUB
2) DECLARE SUB RESULT(N)
A=5555
CALL RESULT(A)
END
SUB RESULT(N)
WHILE N > 0
PRINT N
N = INT(N/10)
WEND
END SUB
A=5555
CALL RESULT(A)
END
SUB RESULT(N)
WHILE N > 0
PRINT N
N = INT(N/10)
WEND
END SUB
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3) DECLARE SUB CHECK()
CALL CHECK
END
SUB CHECK
A=3
C=1
WHILE C <= 5
V=A^C
PRINT V;
C=C+1
WEND
END SUB
CALL CHECK
END
SUB CHECK
A=3
C=1
WHILE C <= 5
V=A^C
PRINT V;
C=C+1
WEND
END SUB
4) DECLARE FUNCTION SUM()
PRINT SUM
END
FUNCTION SUM
FOR N=1 TO 7 STEP 2
LET S = S+N
NEXT N
SUM = S
END FUNCTION
PRINT SUM
END
FUNCTION SUM
FOR N=1 TO 7 STEP 2
LET S = S+N
NEXT N
SUM = S
END FUNCTION
5) DECLARE SUB RESULT(Z)
CLS
Y=2
CALL RESULT(Y)
END
SUB RESULT
FOR A=1 TO 4
PRINT Z*(A^2)
NEXT A
END SUB
CLS
Y=2
CALL RESULT(Y)
END
SUB RESULT
FOR A=1 TO 4
PRINT Z*(A^2)
NEXT A
END SUB
6) DECLARE SUB CHECK(T$)
A$=”*****”
CALL CHECK(A$)
END
SUB CHECK(T$)
FOR K=1 TO LEN(T$)
PRINT LEFT$(T$,K)
NEXT K
END SUB
7) DECLARE FUNCTION EXAM(N)
FOR K=1 TO 5
READ A
PRINT EXAM(A)
NEXT K
DATA 2,4,5,8,3
END
FUNCTION EXAM(N)
IF N MOD 2=0 THEN
EXAM=N^2
ELSE
EXAM=0
END IF
END FUNCTION
A$=”*****”
CALL CHECK(A$)
END
SUB CHECK(T$)
FOR K=1 TO LEN(T$)
PRINT LEFT$(T$,K)
NEXT K
END SUB
7) DECLARE FUNCTION EXAM(N)
FOR K=1 TO 5
READ A
PRINT EXAM(A)
NEXT K
DATA 2,4,5,8,3
END
FUNCTION EXAM(N)
IF N MOD 2=0 THEN
EXAM=N^2
ELSE
EXAM=0
END IF
END FUNCTION
8) DECLARE SUB RESULT(A$)
B$ =”education”
CALL RESULT(B$)
END
SUB RESULT(A$)
FOR I=LEN(A$) TO 1 STEP-2
X$=MID$(A$,I,1)
PRINT X$
NEXT I
END SUB
B$ =”education”
CALL RESULT(B$)
END
SUB RESULT(A$)
FOR I=LEN(A$) TO 1 STEP-2
X$=MID$(A$,I,1)
PRINT X$
NEXT I
END SUB
9) DECLARE SUB SUM()
CALL SUM
END
SUB SUM
a=2
b=2
FOR N=1 TO 3
PRINT a
PRINT b
a=a+b
b=a+b
NEXT N
END SUB
CALL SUM
END
SUB SUM
a=2
b=2
FOR N=1 TO 3
PRINT a
PRINT b
a=a+b
b=a+b
NEXT N
END SUB
10) DECLARE SUB RESULT(N)
A=12345
CALL RESULT(A)
END
SUB RESULT(N)
DO UNTIL N <> 0
PRINT N
N = N\10
LOOP
END SUB
A=12345
CALL RESULT(A)
END
SUB RESULT(N)
DO UNTIL N <> 0
PRINT N
N = N\10
LOOP
END SUB
11) DECLARE FUNCTION RESULT(A$)
B$ =”NEPAL”
PRINT RESULT$(B$)
END
FUNCTION RESULT$(A$)
K=LEN(A$)
DO UNTIL K<1
X$=MID$(A$,K,1)
R$=R$+X$
k=k-2
NEXT I
RESULT$=R$
END FUNCTION
B$ =”NEPAL”
PRINT RESULT$(B$)
END
FUNCTION RESULT$(A$)
K=LEN(A$)
DO UNTIL K<1
X$=MID$(A$,K,1)
R$=R$+X$
k=k-2
NEXT I
RESULT$=R$
END FUNCTION
Write technical terms of the following:
A computer limited within a
room. [2065R]
Rules and format to accept
and transfer data in computer network.
[2066R]
A card used to connect
network cable to computer. [2066S]
The rules that makes the
network communication possible. [2068R]
Physical layout of LAN.
[2069R]
A device that connects
networks having different protocol.
A cable technology that
uses glass (or plastic) threads (fibers) to transmit data.
A computer that handles
requests from other clients.
Standard connectors used
for unshielded twisted-pair cable.
The amount of data that
can be transmitted in a fixed amount of time.
Transmission mode in which
transmission exists in both directions at a time.
Intelligent device used to
connect different computer networks.
Path through which data
signals are transmitted between nodes in computer network.
Network in which all
computers have equal authority.
Choose the best alternatives:
Which refers to the
communication media? [2065R]
UTP cable ii) Fibre optic
cable
iii) Radio wave iv) All
Which one is not a network
topology? [2066R]
Star ii)
Ring
iii) Client
Server iv)
Bus
Which is not a
communication media? [2067R]
Wire `ii)
Microwave
iii) Satellite iv)
NIC
In which topology network
devices are connected through hub? [2067R]
Ring topology ii)
Bus topology
iii) Star topology iv) None of them
Which of the following is
not a protocol? [2068R]
ii) TCP/IP
iii) NOS iv) FTP
Which is not a guided
media? [2066S]
i) UTP cable ii) STP cable
iii) Satellite iv) Fiber Optic
i) UTP cable ii) STP cable
iii) Satellite iv) Fiber Optic
In which communication
media data transfer is high. [2068R]
i) Twisted pair ii) Co-axial cable
iii) Fiber optics iv) Boot sector virus
i) Twisted pair ii) Co-axial cable
iii) Fiber optics iv) Boot sector virus
Which is not a unguided
media? [2069R]
i) Fiber optic ii) Microwave
iii) Infrared iv) Radio wave
iii) Infrared iv) Radio wave
Which of the following
topology share a backbone channel to connect all workstations.
Ring ii) Bus
iii) Star iv)
None of the above
Faster data communication
is possible when using
Fibre optic ii) Co-axial
cable
iii) Microwave
transmission iv) Twisted pair
cable
Which is not a physical
component of computer network?
NIC ii) Hub
iii) Network OS iv) Switch
Which transmission mode
provide unidirectional transmission
Simplex ii) One way
iii) Full duplex iii) Half duplex
Cat 5 is used with which
connector
RJ-11 ii) RJ-45
iii) MT-RJ iv)
None of the above
The device used to
regenerate and strengthen signals
NIC ii) Booster
iii) Hub iv)
Repeater
The combination of bus and
star topology is
i) Mesh topology ii)
Tree topology
iii) Ring topology iv) Mixed topology
The topology in which each
computer is directly connected to either side of the computers
i) Ring topology ii)
Bus topology
iii) Mesh Topology iv) Star topology
Device used to connet
computer to telephone line
i) Router ii)
NIC
iii) Bridge iv)
Modem
Example of unguided
transmission media
Microwave ii) Radio
frequency
iii) None of them iv)
Both i and ii
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MS-Access Revision 0.5 marks questions
1) Choose the correct answer:
Primary Key does not accept………………………
[2065R, 2068R]
i. Text ii. Number iii. Null value iv. None of them
i. Text ii. Number iii. Null value iv. None of them
………………. Is not the data type of MS-Access.
[2065R, 2068R]
i. Number ii. Text iii. Memo iv. Form
i. Number ii. Text iii. Memo iv. Form
…………………….. is the DBMS. [2065R]
i. Fox-pro ii. MS Excel iii. Lotus – 123 iv. All of the above
i. Fox-pro ii. MS Excel iii. Lotus – 123 iv. All of the above
In MS-Access we enter data using……………………..
[2065R]
i. Form ii. Table iii. Report iv. Both (i) & (ii)
i. Form ii. Table iii. Report iv. Both (i) & (ii)
Date/Time occupies……………..bytes of memory.
[2066R]
i. 4 ii. 2 iii. 8 iv. 16
i. 4 ii. 2 iii. 8 iv. 16
The extension of database file in MS-Access
is……………………. [2066R]
i. DBF ii. DBM iii. MDB iv. DMB
i. DBF ii. DBM iii. MDB iv. DMB
The object of MS-Access that is used to
generate hard copy of record. [2066R]
i. Query ii. Table iii. Form iv. Report
i. Query ii. Table iii. Form iv. Report
A…………………….Key uniquely identifies a record.
[2066R]
i. Primary ii. Foreign iii. Composite iv. None
i. Primary ii. Foreign iii. Composite iv. None
Which is not a query? [2067R]
i. Search ii. Select
iii. Update iv. All of the above
i. Search ii. Select
iii. Update iv. All of the above
Collecting multimedia related fields is
called…………… [2067R]
i) Records ii. Table
iii. Forms iv. Query
i) Records ii. Table
iii. Forms iv. Query
The datatype appropriate to store salary
is…………… [2067R]
i. Memo ii. Currency
iii. Text iv. Auto Number
i. Memo ii. Currency
iii. Text iv. Auto Number
……… object of access is used to print
formatted data. [2068R]
i. Query ii. Form
iii. Report iv. Table
i. Query ii. Form
iii. Report iv. Table
In MS-Access data are stored in…………………
[2068R]
i) Form ii) Query
iii) Table iv) All of the above
i) Form ii) Query
iii) Table iv) All of the above
Which of the following is not a database
application? [2069R]
(i) Oracle (ii) Foxpro
(iii) MS-Access (iv) MS-Excel
(i) Oracle (ii) Foxpro
(iii) MS-Access (iv) MS-Excel
Memory space consumed by currency datatype
maximally is…………. [2069R]
i) 2 Bytes ii) 4 Bytes
iii) 8 Bytes iv) 1 GB
i) 2 Bytes ii) 4 Bytes
iii) 8 Bytes iv) 1 GB
The logical data type of MS-Access
is…………………
i. Yes/ No ii. On/Off iii. True/False iv. All
i. Yes/ No ii. On/Off iii. True/False iv. All
Which is the example of database?
i. dBASE ii. MSACCESS iii. Telephone directory iv. All
i. dBASE ii. MSACCESS iii. Telephone directory iv. All
Which component of MS-ACCESS does not allow
entering data?
i. Table ii. Query iii. Form iv. None of them
i. Table ii. Query iii. Form iv. None of them
The maximum Text field size in Access
is……………..
i. 50 ii. 10 iii. 256 iv. 255
i. 50 ii. 10 iii. 256 iv. 255
The object of Access that stores the data
is known as ……………………
i. Query ii. Table iii. Form iv. Report
i. Query ii. Table iii. Form iv. Report
It is organized and formatted view of data
using table.
i. Report ii. Form iii. Table iv. None
i. Report ii. Form iii. Table iv. None
A table is made up of related
i. Text ii. Records iii. Programs iv. Database
i. Text ii. Records iii. Programs iv. Database
Storage size of currency data type is
………………. Bytes.
i. 2 ii. 4 iii. 8 iv. 1
i. 2 ii. 4 iii. 8 iv. 1
The default data type of MS-Access
is…………………...
i. Number ii. Text iii. Memo iv. Auto Number
i. Number ii. Text iii. Memo iv. Auto Number
What is the suitable data type to store
email addresses?
i. Memo ii. Text iii. OLE iv. Hyperlink
i. Memo ii. Text iii. OLE iv. Hyperlink
The caption can have maximum of ……………………..
characters.
i. 2062 ii. 2048 iii. 1048 iv. 1062
i. 2062 ii. 2048 iii. 1048 iv. 1062
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2. State true or false:
A query cannot be the source for a form.
Primary key field may contain the same
value in two records.
A field cannot be declared without data
type.
The extension of MS-Access database file is
.BDF [2066S]
Memo datatype cannot be indexed. [2066S]
The default size of text datatype is 50.
[2066S]
Hyperlink field type is used to store
photographs.
A report can be used to delete records from
a table.
A row in a table is called a field.
The format field property specifies a
pattern for all data to be entered in a field.
The select query makes changes to many
records in just one operation.
A
query is used to select fields and records from many tables. [2065S]
MS-ACCESS is a spreadsheet software.
[2065S]
Index decreases the speed of the query and
sort operations. [2065S]
The data in primary key field need to be
unique and not null. [2065S]
3. Fill in the blanks:
………………… query is used to change data in a
table.
We can change data type of a field in
……………… view.
Storage size of logical data type is
…………………
Update query is an example of
…………………..query.
Field name can be of maximum
………………….Characters.
A single record is also known as …………………..
Default field size of number data type is
called…………….
Default field size of text data type is
called………………..
. ……………….. data type is used to store sound
and video.
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