Paper DSC 103: FUNDAMENTALS OF INFORMATION TECHNOLOGY
Classification Of Computers
Q.5)Explain
classification of computers?
Ans: Computers are
broadly classified into two categories depending upon the logic used in their
design as:
Analog
computers: In
analog computers, data is recognized as a continuous measurement of a physical
property like voltage, speed, pressure etc. Readings on a dial or graphs are
obtained as the output,
ex.
Voltage, temperature; pressure can be measured in this way.
Digital
Computers: These
are high speed electronic devices. These devices are programmable. They process
data by way of mathematical calculations, comparison, sorting etc. They accept
input and produce output as discrete signals representing high (on) or low
(off) voltage state of electricity. Numbers, alphabets, symbols are all represented
as a series of 1s and Os.
Classification
of digital computers is done on the basis of their capacity to access memory
and size like:
•Small
Computers:
I)
Microcomputers:
Microcomputers are generally referred to as Personal Computers (PCs). They have
Smallest memory and less power. They are widely used in day to day applications
like office automation, and professional applications, ex. PCAT, Pentium etc.
II) Note Book
and Laptop Computers:
These are portable in nature and are battery operated. Storage devices like
CDs, floppies etc. and output devices like printers can be connected to these
computers. Notebook computers are smaller in physical size than lap top
computers. However, both have powerful processors, support graphics, and can
accept mouse driven input.
III) Hand Held
Computers: These types of computers are mainly used in applications like
collection of field data. They are even smaller than the note book computers.
•Hybrid
Computers:
Hybrid Computers are a combination of Analog and Digital computers. They
combine the speed of analog computers and accuracy of digital computers. They
are mostly used in specialized applications where the input data is in an
analog form i.e. measurement. This is converted into digital form for further processing.
The computers accept data from sensors and produce output using conventional
input/output devices.
•
Mini Computers:
Mini computers are more powerful than the micro computers. They have higher
memory capacity and more storage capacity with higher speeds. These computers
are mainly used in process control systems. They are mainly used in applications
like payrolls, financial accounting, Computer aided design etc.
ex.
VAX, PDP-11
•Mainframe
Computers:
Main frame computers are very large computers which process data at very high
speeds of the order of several million instructions per second. They can be
linked into a network with smaller computers, micro computers and with each
other. They are typically used in large organizations, government departments
etc.
ex.
IBM4381, CDC
•
Super Computers:
A super computer is the fastest, most powerful and most expensive computer
which is used for complex tasks that require a lot of computational power. Super
computers have multiple processors which process multiple instructions at the same
time. This is known as parallel processing. These computers are widely used in very
advanced applications like weather forecasting, processing geological data etc.
ex.
CRAY-2, NEC - 500, PARAM.
Applications of Computer
Q.6)
Explain applications of computer?
Ans:
1. Educational
Institutions Computers
are incorporated in various educational institutions like schools and colleges
for easy learning.
The
computer based learning allows students to gain knowledge about specific topic.
The development of computers helped the students in preparing projects and
essays, in performing mathematical calculations etc.
2. Science: Computers
are used by scientist in the fields of research and development. It facilitates
in analyzing new theories, predicting natural calamities like tsunami and
earthquake.
3. Communication: Computers
enable multiple users to transfer data from one system to another system.
Internet is considered as a common communication media that provides
interactions among various users.
4. Business: Computers
are used in various business organizations in order to maintain records of
their accounts, their inventory and about profit and loss. In addition to this,
computers can also be used for conducting meetings among users residing on
different remote locations via web conferencing. Apart from this, computer and
internet also helps in carrying out online business.
5.
Banking: Computers are used in banks to facilitate online banking. This
helps in easy transfer of money from one account to another, bill payments etc.
Beside this, computers are also used for maintaining records of financial
transactions being performed in bank.
6. Entertainment: Computers
can be incorporated in entertainment industries for creating interactive
graphics, animations and video games.
7.
Government: Computers can also be used in various government departments like
revenue, defense, industry, census, police etc., for betterment of people. The
term e-governance is extensively growing popularly in the world.
8. Health:
Computers are used in hospitals so as to,
(i) Keep track of
patients records and generating bills
(ii) Diagnose
different diseases and ailments
(iii)Monitor the
patients condition using various analog and digital devices
(iv) Examine the
internal parts of the body.
9. Military: Computers
are useful in designing weapons, targeting ballistic muscles and controlling
access to atomic bomb etc.
10.
Weather Forecast: Computers are used to analyze and forecast the weather.
limitations of computer
· The
computer cannot think on its own, since it does not have its own brain. It can
only do what is has been programmed to do.
· The
computers do not learn from previous experience nor can they arrive at a
conclusion without going through all the intermediate steps.
Role of I/O devices in a computer system
·Input/ Output devices (I/O devices) are used to communicate with
the computer.
· They surround the central processing unit.
·For this reason, they are called peripherals or peripheral devices
of computer.
·The role of these devices is to input the data to the computer are
different from output devices.
·However, some I/O devices are capable of performing both input and
output functions.
· I/O devices are slower in terms of speed when compared to CPU.
· The reason for this is the movement of mechanical parts present in
these devices.
Input Units:
Q.7) Write a detailed
note on input devices in a computer?(VIMP)
Input
devices are:
1.
Keyboard
2.
Mouse
3.
Scanner
4.
Joystick
5.
Light Pen
6.
Digitizer
7.
Microphone
8.
Magnetic Ink Character Recognition (MICR)
9.
Optical Character Reader (OCR)
10.
Digital Camera
Keyboard
A keyboard
is the primary input device. It can be used to enter the text input. A
standard keyboard contains about 100 keys. It contains Typing keys, numeric
keypad, Control keys, function keys, cursor keys and special purpose keys. The
computer keyboard uses the QWERTY key arrangement.
The keys on the keyboard include :
A-Z : Used to enter alphabets
0-9 : Used to enter numbers
Up, Down, Left,
Right(Arrow Keyes): To Move the cursor in the specified direction
F1-F12 : Special Function Keys
PgUp/PgDn : To move cursor up or down by one page enter/To move cursor to a new line
Shift : A Special key To Select the other option shown normal character on the
same
key Num Lock : Activates the keypad on the right side of the keyboard. In the normal mode
this numeric pad works as per the function written below the number on the key
Pointing Devices
Mouse A Mouse is a graphical
input device. You can move the mouse around a surface and controls the pointer.
The mouse is a pointing device. The
mouse is used to control and manipulate cursor movement on the monitor. The
mouse usually has three or four buttons on it and a roller ball which signals
the movements made by the mouse on a flat surface.
The
various types of mouse in use are
· - Mechanical
mouse
· - Optical
mouse
· - Opt
mechanical mouse
By
using the mouse, you can perform:
I.
Clicking
II.
Double-Clicking
III.
Dragging
IV. Right
Clicking
Joystick
:
Joystick
is also a pointing device, which is used to move the cursor position on a
monitor screen. It is a stick having a spherical ball at its both lower and
upper ends. The lower spherical ball moves in a socket. The joystick can be
moved in all four directions. The function of the joystick is similar to that
of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing
computer games.
Light
Pen : Light
pen is a pointing device similar to a pen. It is used to select a displayed
menu item or draw pictures on the monitor screen. It consists of a photocell
and an optical system placed in a small tube.
When
the tip of a light pen is moved over the monitor screen and the pen button is
pressed, its photocell sensing element detects the screen location and sends
the corresponding signal to the CPU.
Touch
Screen: Touch
screen serve as an input device that detects the presence and location of a
touch within the display area. It consists of a special surface screen on which
the objects are pointed and selected. It is very sensitive to objects like
finger or stylus.
Track
Ball The track ball
uses a hard sphere to control cursor movement. The bail can be rotated in any
direction by hand and this is translated into a digital signal to control the
cursor movement on the screen.
Scanner A
scanner is an input device. It can scan a document or an image into the computer's
memory. Scanner
is device used to input text/pictures/ any other data as images (graphic mode).
Scanners
are 2 types. They are Flat-bed scanner and Hand-held scanner.
1) Flat-bed
Scanner:
Flat-bed scanner is one of the most commonly used input device for scanning the
documents. It is similar to a xerox machine. It is a box that consists of a
transparent glass plate at the top and a covering lid. In a flat-bed scanner, a
document can be scanned by placing it on to the glass-plate and closing the lid.
2)
Hand-held Scanner:
Hand-held scanner carries a set of LEDs. To scan a page, user needs to manual
hold the scanner in the hand and slowly drag it over the page. The quality of
scanning completely relies on the steadiness of scanning. For this reason, it
is less preferable over flat-bed scanners.
Optical
Character Recognition (OCR):
·
An
optical card reader works in the similar way as the human eye.
·
It
uses a device that reads preprinted characters in a particular font and
converts them to digital code.
·
Data
can be saved and transferred to the computer system to be used in activities .
(ii)
Optical Mark Recognition (OMR)
·
The process of
extracting the data from marked fields like fill-in fields of checkboxes is
called OMR.
·
It
contains mark sensing to scan and translate a series of pen or pencil marks in
OMR sheet into computer readable form based on its location.
·
An
example of it is the objective type multiple choice question paper of bank
recruitment exam.
·
A
computerized optical mark reader generates scores by identifying the position
of the mark.
(iii)
Magnetic Ink Character Reader (MICR)
·
MICR input
device is generally used in banks as there are large number of cheques to be
processed every day.
·
The
bank's code number and cheque number are printed on the cheques with a special
type of ink that contains particles of magnetic material that are machine
readable.
·
This
reading process is called Magnetic Ink Character Recognition (MICR). The main
advantages of MICR is that it is fast and less error prone.
·
They
decrease the chances of check fraud.
(iii)Barcode
Reader
·
Bar Code Reader
is a device used for reading bar coded data (data in the form of light and dark
lines). Bar coded data is generally used in labeling goods, numbering the
books, etc. It may be a handheld scanner or may be embedded in a stationary
scanner.
·
Bar
Code Reader scans a bar code image, converts it into an alphanumeric value,
which is then fed to the computer that the bar code reader is connected to.
Digitizer
:
A
digitizer converts a graphical or pictorial data into digital form which can be
directly entered and stored in a computer. A digitizer is also called as a
graphics tablet.
Terminals and its types
Terminal
or visual Display Terminal (VDT) is a device capable of performing input and
output operations.
It
carries a monitor (screen) and a keyboard for output and input respectively.
The
functionality of older terminals were dependent on main frame computers where
they are connected over a cable.
However,
in personal computers, they perform independently.
Following
are the various types of terminals,
1)
Dumb Terminal:
The terminal which is capable of providing only input from keyboard to the
computer and displaying output on the screen is called a dumb terminal. It is
not capable of processing any input provided by the user. It is used only on
mainframe computers
2)
Smart Terminal:
The terminal which is capable of performing limited amount processing a part
from input/output operations is called smart terminal. These processing
capabilities usually include editing and verifying the data. A limitation in
these terminals is the lack of programming capability.
3)
Intelligent Terminal:
The terminal which carries an inbuilt processor is called intelligent terminal
terminal or user programmable terminal. These terminals act as personal
computers and are connected over a LAN through switches. These terminals can
access mainframe computers and can also perform their own set of operations. It
carries keyboard, monitor, communication links, memory and software.
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Classification Of Computers
Q.5)Explain
classification of computers?
Ans: Computers are
broadly classified into two categories depending upon the logic used in their
design as:
Analog
computers: In
analog computers, data is recognized as a continuous measurement of a physical
property like voltage, speed, pressure etc. Readings on a dial or graphs are
obtained as the output,
ex. Voltage, temperature; pressure can be measured in this way.
Digital
Computers: These
are high speed electronic devices. These devices are programmable. They process
data by way of mathematical calculations, comparison, sorting etc. They accept
input and produce output as discrete signals representing high (on) or low
(off) voltage state of electricity. Numbers, alphabets, symbols are all represented
as a series of 1s and Os.
Classification
of digital computers is done on the basis of their capacity to access memory
and size like:
•Small
Computers:
I)
Microcomputers:
Microcomputers are generally referred to as Personal Computers (PCs). They have
Smallest memory and less power. They are widely used in day to day applications
like office automation, and professional applications, ex. PCAT, Pentium etc.
II) Note Book
and Laptop Computers:
These are portable in nature and are battery operated. Storage devices like
CDs, floppies etc. and output devices like printers can be connected to these
computers. Notebook computers are smaller in physical size than lap top
computers. However, both have powerful processors, support graphics, and can
accept mouse driven input.
III) Hand Held
Computers: These types of computers are mainly used in applications like
collection of field data. They are even smaller than the note book computers.
•Hybrid
Computers:
Hybrid Computers are a combination of Analog and Digital computers. They
combine the speed of analog computers and accuracy of digital computers. They
are mostly used in specialized applications where the input data is in an
analog form i.e. measurement. This is converted into digital form for further processing.
The computers accept data from sensors and produce output using conventional
input/output devices.
•
Mini Computers:
Mini computers are more powerful than the micro computers. They have higher
memory capacity and more storage capacity with higher speeds. These computers
are mainly used in process control systems. They are mainly used in applications
like payrolls, financial accounting, Computer aided design etc.
ex. VAX, PDP-11
•Mainframe
Computers:
Main frame computers are very large computers which process data at very high
speeds of the order of several million instructions per second. They can be
linked into a network with smaller computers, micro computers and with each
other. They are typically used in large organizations, government departments
etc.
ex. IBM4381, CDC
•
Super Computers:
A super computer is the fastest, most powerful and most expensive computer
which is used for complex tasks that require a lot of computational power. Super
computers have multiple processors which process multiple instructions at the same
time. This is known as parallel processing. These computers are widely used in very
advanced applications like weather forecasting, processing geological data etc.
ex. CRAY-2, NEC - 500, PARAM.
Applications of Computer
Q.6)
Explain applications of computer?
Ans:
1. Educational Institutions Computers are incorporated in various educational institutions like schools and colleges for easy learning.
The
computer based learning allows students to gain knowledge about specific topic.
The development of computers helped the students in preparing projects and
essays, in performing mathematical calculations etc.
3. Communication: Computers
enable multiple users to transfer data from one system to another system.
Internet is considered as a common communication media that provides
interactions among various users.
4. Business: Computers
are used in various business organizations in order to maintain records of
their accounts, their inventory and about profit and loss. In addition to this,
computers can also be used for conducting meetings among users residing on
different remote locations via web conferencing. Apart from this, computer and
internet also helps in carrying out online business.
5.
Banking: Computers are used in banks to facilitate online banking. This
helps in easy transfer of money from one account to another, bill payments etc.
Beside this, computers are also used for maintaining records of financial
transactions being performed in bank.
6. Entertainment: Computers
can be incorporated in entertainment industries for creating interactive
graphics, animations and video games.
7.
Government: Computers can also be used in various government departments like
revenue, defense, industry, census, police etc., for betterment of people. The
term e-governance is extensively growing popularly in the world.
8. Health:
Computers are used in hospitals so as to,
(i) Keep track of
patients records and generating bills
(ii) Diagnose
different diseases and ailments
(iii)Monitor the
patients condition using various analog and digital devices
(iv) Examine the
internal parts of the body.
9. Military: Computers
are useful in designing weapons, targeting ballistic muscles and controlling
access to atomic bomb etc.
10. Weather Forecast: Computers are used to analyze and forecast the weather.
limitations of computer
· The
computer cannot think on its own, since it does not have its own brain. It can
only do what is has been programmed to do.
· The computers do not learn from previous experience nor can they arrive at a conclusion without going through all the intermediate steps.
Role of I/O devices in a computer system
·Input/ Output devices (I/O devices) are used to communicate with
the computer.
· They surround the central processing unit.
·For this reason, they are called peripherals or peripheral devices
of computer.
·The role of these devices is to input the data to the computer are
different from output devices.
·However, some I/O devices are capable of performing both input and
output functions.
· I/O devices are slower in terms of speed when compared to CPU.
· The reason for this is the movement of mechanical parts present in
these devices.
Input Units:
Q.7) Write a detailed
note on input devices in a computer?(VIMP)
Input
devices are:
1.
Keyboard
2.
Mouse
3.
Scanner
4.
Joystick
5.
Light Pen
6.
Digitizer
7.
Microphone
8.
Magnetic Ink Character Recognition (MICR)
9.
Optical Character Reader (OCR)
10.
Digital Camera
Keyboard
A keyboard
is the primary input device. It can be used to enter the text input. A
standard keyboard contains about 100 keys. It contains Typing keys, numeric
keypad, Control keys, function keys, cursor keys and special purpose keys. The
computer keyboard uses the QWERTY key arrangement.
The keys on the keyboard include :
A-Z : Used to enter alphabets
0-9 : Used to enter numbers
Up, Down, Left,
Right(Arrow Keyes): To Move the cursor in the specified direction
F1-F12 : Special Function Keys
PgUp/PgDn : To move cursor up or down by one page enter/To move cursor to a new line
Shift : A Special key To Select the other option shown normal character on the
same
key Num Lock : Activates the keypad on the right side of the keyboard. In the normal mode this numeric pad works as per the function written below the number on the key
Pointing Devices
Mouse A Mouse is a graphical
input device. You can move the mouse around a surface and controls the pointer.
The mouse is a pointing device. The
mouse is used to control and manipulate cursor movement on the monitor. The
mouse usually has three or four buttons on it and a roller ball which signals
the movements made by the mouse on a flat surface.
The
various types of mouse in use are
· - Mechanical mouse
· - Optical mouse
· - Opt mechanical mouse
By
using the mouse, you can perform:
I.
Clicking
II.
Double-Clicking
III.
Dragging
IV. Right Clicking
Joystick
:
Joystick is also a pointing device, which is used to move the cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. The function of the joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games.
Light Pen : Light pen is a pointing device similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube.
When the tip of a light pen is moved over the monitor screen and the pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU.
Touch Screen: Touch screen serve as an input device that detects the presence and location of a touch within the display area. It consists of a special surface screen on which the objects are pointed and selected. It is very sensitive to objects like finger or stylus.
Track Ball The track ball uses a hard sphere to control cursor movement. The bail can be rotated in any direction by hand and this is translated into a digital signal to control the cursor movement on the screen.
Scanner A scanner is an input device. It can scan a document or an image into the computer's memory. Scanner is device used to input text/pictures/ any other data as images (graphic mode).
Scanners
are 2 types. They are Flat-bed scanner and Hand-held scanner.
·
An
optical card reader works in the similar way as the human eye.
·
It
uses a device that reads preprinted characters in a particular font and
converts them to digital code.
·
Data
can be saved and transferred to the computer system to be used in activities .
(ii)
Optical Mark Recognition (OMR)
·
The process of
extracting the data from marked fields like fill-in fields of checkboxes is
called OMR.
·
It
contains mark sensing to scan and translate a series of pen or pencil marks in
OMR sheet into computer readable form based on its location.
·
An
example of it is the objective type multiple choice question paper of bank
recruitment exam.
·
A
computerized optical mark reader generates scores by identifying the position
of the mark.
(iii)
Magnetic Ink Character Reader (MICR)
·
MICR input
device is generally used in banks as there are large number of cheques to be
processed every day.
·
The
bank's code number and cheque number are printed on the cheques with a special
type of ink that contains particles of magnetic material that are machine
readable.
·
This
reading process is called Magnetic Ink Character Recognition (MICR). The main
advantages of MICR is that it is fast and less error prone.
·
They
decrease the chances of check fraud.
(iii)Barcode
Reader
·
Bar Code Reader
is a device used for reading bar coded data (data in the form of light and dark
lines). Bar coded data is generally used in labeling goods, numbering the
books, etc. It may be a handheld scanner or may be embedded in a stationary
scanner.
·
Bar
Code Reader scans a bar code image, converts it into an alphanumeric value,
which is then fed to the computer that the bar code reader is connected to.
Digitizer :
A digitizer converts a graphical or pictorial data into digital form which can be directly entered and stored in a computer. A digitizer is also called as a graphics tablet.
Terminals and its types
Terminal
or visual Display Terminal (VDT) is a device capable of performing input and
output operations.
It
carries a monitor (screen) and a keyboard for output and input respectively.
The
functionality of older terminals were dependent on main frame computers where
they are connected over a cable.
However,
in personal computers, they perform independently.
Following
are the various types of terminals,
1)
Dumb Terminal:
The terminal which is capable of providing only input from keyboard to the
computer and displaying output on the screen is called a dumb terminal. It is
not capable of processing any input provided by the user. It is used only on
mainframe computers
2)
Smart Terminal:
The terminal which is capable of performing limited amount processing a part
from input/output operations is called smart terminal. These processing
capabilities usually include editing and verifying the data. A limitation in
these terminals is the lack of programming capability.
3)
Intelligent Terminal:
The terminal which carries an inbuilt processor is called intelligent terminal
terminal or user programmable terminal. These terminals act as personal
computers and are connected over a LAN through switches. These terminals can
access mainframe computers and can also perform their own set of operations. It
carries keyboard, monitor, communication links, memory and software.
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