IGNOU BCA revised syllabus solved assignments are finally making their way to http://myignoubca.blogspot.com . Here you will find some solved questions of BCS-011 "Computer Basics and PC Software".
(a) Explain the different generations of computer? List some of
the applications areas of computer.
In terms of computer hardware, there are at least four generations of digital computer
systems.
First generation computers were introduced shortly after World War II. Based on
vacuum tube technology, these were large, required lots of power, generated plenty of
heat, and needed constant maintenance.
Second generation computers were introduced in 1959, with the release of the IBM
7090. These used transistors instead of vacuum tubes, resulting in a dramatic decrease in
cost, size, and power consumption as well as an increase in reliability.
Third generation computers, introduced in 1964 with the announcement of the IBM
360, were the first to use integrated circuits (ICs). An IC consists of a large number of
electronic circuits etched onto a single semiconductor chip. This use of microchips led to
more dramatic drops in cost, size, and power consumption, and to greater reliability.
By 1971, the first general purpose processor-on-a-chip or microprocessor had been
released: this was a major breakthrough in chip architecture. Second, large scale
integration (LSI) had been achieved, delivering a major increase in chip density (number
of circuit elements contained on the one chip). Although LSI led to size reductions, its
primary purpose was to speed up processing by reducing the distances that electrons had
to travel. These advances introduced the fourth generation of computers. In 1975, very
large scale integration (VLSI) was achieved, packing over 100,000 transistors onto a
single chip.
Although some modern CPUs operate at frequencies in excess of 3 GHz, heat
generation problems indicate that much higher frequencies may be unattainable. Instead,
the main contributor to future performance boosts is likely to come from multicore
technology, packing many processors onto a single chip. In February 2008, Intel
announced its Itanium quad-core CPU (code named “Tukwila”) with a record-busting two
billion transistors. The year 2008 also saw the introduction of 8-core chips, and chips with
much higher core counts are expected in the near future.
Application areas of computers:
Home
Office
News Agency
Airport
Railway Station
Banks
Post Office
Schools
College/University
Research/Laboratory
Media/Movies
Hotels
Hospitals
Library
(b) What is Von Neumann Architecture? Explain the functions
of different components on von Neumann machine. Why is a
computer known as data processor?
von Neumann architecture - A computer architecture conceived by mathematician John von Neumann,
which forms the core of nearly every computer system in use today (regardless of size). In contrast to
a Turing machine, a von Neumann machine has a random-access memory (RAM) which means that each
successive operation can read or write any memory location, independent of the location accessed by the
previous operation.
A von Neumann machine also has a central processing unit (CPU) with one or more registers that hold
data that are being operated on. The CPU has a set of built-in operations (its instruction set) that is far
richer than with the Turing machine, e.g. adding two binary integers, or branching to another part of a
program if the binary integer in some register is equal to zero (conditional branch).
The CPU can interpret the contents of memory either as instructions or as data according to the fetch-
execute cycle.
Von Neumann considered parallel computers but recognized the problems of construction and hence
settled for a sequential system. For this reason, parallel computers are sometimes referred to as non-von
Neumann architectures.
A von Neumann machine can compute the same class of functions as a universal Turing machine.
Computer is a digital data processor. In practice this means that all analogue data (text, sound,
pictures) gets translated into masses of 0’s and 1’s. These numbers (binary values) exist as tiny
electrical charges in microscopic circuits, where a transistor can take on two states: charged or not
charged. This is one picture of a bit, which you can say is either turned on or off.
(c) Explain the purpose of a motherboard in a computer?
The motherboard is the main printed circuit board and contains the buses, or electrical pathways,
found in a computer. These buses allow data to travel between the various components that comprise
a computer. A motherboard is also known as the system board, the backplane, or the main board.
The motherboard accommodates the central processing unit (CPU), RAM, expansion slots, heat
sink/fan assembly, BIOS chip, chip set, and the embedded wires that interconnect the motherboard
components. Sockets, internal and external connectors, and various ports are also placed on the
motherboard.
The form factor of motherboards pertains to the size and shape of the board. It also describes the
physical layout of the different components and devices on the motherboard. Various form factors
exist for motherboards.
An important set of components on the motherboard is the chip set. The chip set is composed of
various integrated circuits attached to the motherboard that control how system hardware interacts
with the CPU and motherboard. The CPU is installed into a slot or socket on the motherboard. The
socket on the motherboard determines the type of CPU that can be installed.
The chip set of a motherboard allows the CPU to communicate and interact with the other components
of the computer, and to exchange data with system memory, or RAM, hard disk drives, video cards,
and other output devices. The chip set establishes how much memory can be added to a motherboard.
The chip set also determines the type of connectors on the motherboard.
Most chip sets are divided into two distinct components, Northbridge and Southbridge. What each
component does varies from manufacturer to manufacturer, but in general the Northbridge controls
access to the RAM, video card, and the speeds at which the CPU can communicate with them. The
video card is sometimes integrated into the Northbridge. The Southbridge, in most cases, allows the
CPU to communicate with the hard drives, sound card, USB ports, and other I/O ports.
Explain the need of ASCII and Unicode?
(d)
ASCII
ASCII is an acronym for "american standard code for information interchange". used for storing/displaying
text, simple formatting and a few other control characters. below is the ascii table, giving the decimal
value, the hexidecimal value, the glyph and the binary value for each. the binary value is how its stored
on a disk.
UNICODE
A double byte character system designed to store and display a much wider range of letters.(65,536) the
extra include foreign languages and mathematical/scientific symbols, plus space for future expansion.
all ascii characters still exist in unicode, either prefixed or suffixed by a null.
What is need of memory in a computer? Also explain the need of a memory
(e)
hierarchy.
In computing, memory refers to the physical devices used to store programs (sequences of instructions)
or data (e.g. program state information) on a temporary or permanent basis for use in a computer or other
digital electronic device. The term primary memory is used for the information in physical systems which
are fast (i.e. RAM), as a distinction from secondary memory, which are physical devices for program and
data storage which are slow to access but offer higher memory capacity. Primary memory stored on
secondary memory is called "virtual memory".
The term "storage" is often (but not always) used in separate computers of traditional secondary memory
such as tape, magnetic disks and optical discs (CD-ROM and DVD-ROM). The term "memory" is often
(but not always) associated with addressable semiconductor memory, i.e. integrated circuits consisting of
silicon-based transistors, used for example as primary memory but also other purposes in computers and
other digital electronic devices.
There are two main types of semiconductor memory: volatile and non-volatile. Examples of non-volatile
memory are flash memory (sometimes used as secondary, sometimes primary computer memory) and
ROM/PROM/EPROM/EEPROM memory (used for firmware such as boot programs). Examples of volatile
memory are primary memory (typically dynamic RAM memory, DRAM), and fast CPU cache memory
(typically static RAM memory, SRAM, which is fast but energy-consuming and offer lower memory
capacity per area unit than DRAM) .
Memory Hierarchy:
Explain with examples, the different types of main memory in computer systems.
(f)
Every computer comes with a certain amount of physical memory, usually referred to as main memory or
RAM. You can think of main memory as an array of boxes, each of which can hold a single byte of
information. A computer that has 1 megabyte of memory, therefore, can hold about 1 million bytes (or
characters) of information.
There are several different types of memory:
RAM (random-access memory): This is the same as main memory. When used by itself, the term
RAM refers to read and write memory; that is, you can both write data into RAM and read data
from RAM. This is in contrast to ROM, which permits you only to read data. Most RAM is volatile,
which means that it requires a steady flow of electricity to maintain its contents. As soon as the
power is turned off, whatever data was in RAM is lost.
ROM (read-only memory): Computers almost always contain a small amount of read-only
memory that holds instructions for starting up the computer. Unlike RAM, ROM cannot be written
to.
PROM (programmable read-only memory): A PROM is a memory chip on which you can store a
program. But once the PROM has been used, you cannot wipe it clean and use it to store
something else. Like ROMs, PROMs are non-volatile.
EPROM (erasable programmable read-only memory): An EPROM is a special type of PROM that
can be erased by exposing it to ultraviolet light.
EEPROM (electrically erasable programmable read-only memory): An EEPROM is a special type
of PROM that can be erased by exposing it to an electrical charge.
(g) What are different input/output (I/O) devices in a computer?
Explain any two output devices.
An input device is any hardware device that sends data to the computer, without any input devices, a
computer would only be a display device and not allow users to interact with it, much like a TV. In the
picture to the right, is a Logitech trackball mouse and an example of an input device. Below is a complete
listing of all the different computer input devices that can be used on a computer.
Barcode reader
Digital camera
Gamepad
Joystick
Keyboard
Microphone
MIDI keyboard
Mouse (pointing device)
Remote
Scanner
Webcam
Any peripheral that receives or displays output from a computer. In the picture to the right, is an inkjet
printer and a good example of an output device that can make a hard copy of anything on a computer.
Below is a listing of all the different computer output devices found on a computer.
Flat panel
Monitor
Printer
Projector
Sound card
Speakers
Video card
What is a port? Differentiate between serial and parallel port.
(h)
In computer networking, the term port can refer to either physical or virtual connection points.
Physical network ports allow connecting cables to computers, routers, modems and other peripheral
devices.
Like a single laned road (serial) and a highway (parallel).
Although the data is going in one direction, the data is sent bit-by-bit with serial communication (single
lane road-car by car). With parallel the data is moved multi bits at a time (a multi lane highway going in
the same direction with full of traffic)
Serial communication means less number of wire and it is slow, one by one bit of message signal is send
to receiver. Parallel communication has so many numbers of wire & it is fast.
Serial communication: Modem.
Parallel Communication: Printer.
i) What are different types of PC? Explain the configuration of a PC
with the help of an example.
There are mostly two type of PCs:
1. Stationary and 2. Mobile
Stationary Computers: Workstations, Desktop Computers, NETTops etc.
Mobile: Laptops, NetBooks, Tablet PC, Ultra mobile PC, Pocket PC.
Configuration of a computer:
configuration is an arrangement of functional units according to their nature, number, and chief
characteristics. Often, configuration pertains to the choice of hardware, software, firmware, and
documentation. The configuration affects system function and performance.
For example: Configuration of a home PC is given below:
PC Type : PC
OS: Windows 7 Ultimate
Bit: 32 bit
Processor: Intel
Processor Config: Core 2 Duo
Mother Board: GigaByte 945 S Series
RAM: Transcend
RAM Size: 3Gb DDR2
HDD Size: 160Gb + External HDD 500Gb
HDD Company: Seagate
DVD ROM: Samsung ( Not working now , going to buy LG)
Memory Card Reader: N/A
TV Tuner Card: Gonna buy it soon
Graphics Card: NVidia XForce
Graphics Card Size:512Mb
Speakers/Monitor/Keyboard: Creative 2 Small Sized Speakers/Samsung 17"/Logitech Mouse+Keyboard
Any other extra accessories: None ..
g) What is software component of a PC? Explain use of
Disk Defragmenter utility Software.
Computer Software:
Written programs or procedures or rules and associated documentation pertaining to the operation of a
computer system and that are stored in read/write memory.
Disk Defragmenter Utility:
Disk Defragmenter MMC is based on the full retail version of Executive Software Diskeeper. The version
that is included with Windows XP and later provides limited functionality in maintaining disk performance
by defragmenting volumes that use the FAT, FAT32, or NTFS file system.
To start Disk Defragmenter MMC, use one of the methods that is described below:
Method: Use the Properties of Your Local Disk
Open My Computer.
Right-click the local disk volume that you want to defragment, and then click Properties.
On the Tools tab, click Defragment Now.
Click Defragment.
Question 2:
(a) Why do you need Computer Software? What are the software trends
in the present time? What are the advantages and disadvantages of using
Open Source Software? Make a list of at least three useful Open Source
Software that are used in Software development. List the basic features
of each of these software.
Answer:
Software is the easiest way for users to interact with the hardware of a system. With modern day
computers, it would be impossible to accomplish anything without software. The best you could
accomplish without software would be clocks (analog and basic digital) and things like that.
Software is what allows complicated computations.
Software Trends:
Software are available in different trends now a days commonly there are two trends of software. First is
paid type software or known as shareware and second is open source software known as freeware.
Advantage #1 - Stability
If you have used other operating systems, once you have made the switch to Linux, you will notice that
Linux has an edge over Windows here. I can remember rebooting Windows many times over the years,
because an application crashed, and I couldn't continue working. Linux can crash also, but it is much
harder to do. If an application crashes in Linux, it will usually not harm the kernel or other processes.
Advantage #2 - Free Software
Most software can be obtained without cost for Linux. For example, one thing that has kept people from
Linux is the lack of office software. That has changed with Open Office, and now you can edit documents
and presentations from the popular Microsoft software. The conversion isn't 100% perfect, but it has
worked remarkably well in allowing me to correspond and use documents that people send me via e-mail
or the web.
Advantage #3 - Runs on old hardware
If you have an old 386 or 486 laying around collecting dust, you can use this to run Linux. I remember
running Linux just fine on a Pentium 100 with a 1 GB disk drive, and 16 MB of memory. One use of an
old machine like that could be a file server. Just go to your computer store, buy a large hard disk (as long
as your old stuff can support it), and you can make a great storage server. With all the digital pictures and
movies around today, this could be a great use for Linux. Look into using Samba, a server application for
Linux that allows you to make your machine share the disk as a Windows share.
Advantage #4 - Security
Linux has the advantage of the code being in the public domain. This can be a double-edged sword; while
you can look at the code, and developers can fix holes rapidly, it also means hackers can find bad code. I
have been very impressed with the security of Linux, and the programs that run on it. I think having the
code out in the open, and the ability to fix things yourself if necessary is a big plus. Who likes to work
blind? With some distributions, on installation the computer will ask you what levels of security you
would like for your system. You can be very trusting, or you can be paranoid. Linux gives you this
flexiblity.
Disadvantage #1 - Learning curve
I won't lie to you; Linux is going to take some time to learn. I know that our society likes to be instantly
gratified. Learning Linux is definitely worth your time, but to really master it, you will need to spend
some good time in front of your machine tinkering with things. Don't expect to be an expert after reading
something like "Linux for Dummies". If you are contemplating this for your company, you will need to
budget some money for training and learning time.
Disadvantage #2 - Equivalent programs
While I gave the example before of an office suite of programs that is working well, there are still
applications that do not exist in Linux. Thankfully, this list has become much more narrow in recent
months. You will want to think carefully when you switch to Linux about what programs you currently
use, and if they have Linux support for them. It may not make sense for you to switch if you are going to
spend tons of time converting databases and application data.
Disadvantage #3 - More technical ability needed
You will want to make sure that you train someone in Linux really well. Alternately, you could hire
someone who has experience with Linux. A good Linux administrator needs to be on hand as you start to
migrate your systems over. This is a disadvantage financially, at least in the beginning. You may find
over time, however, that you only need a temporary administrator to handle the routine tasks.
Disadvantage #4 - Not all hardware compatible
Some of the latest and greatest hardware that is being produced is not compatible with Linux. At least, not
yet. The people that contribute program code and drivers to the Linux kernel are great at including
support fairly quickly. Until that time, not everything you buy for hardware in your system may work.
I've had to rely on third-party drivers and other means to make hardware like a new Ethernet card work.
Eventually, the support will be built in. One thing you can do is before your purchase, ask if the hardware
vendor has support for Linux. Some manufacturers do write their own Linux drivers and distribute them
with your purchase, making it very easy to integrate with your existing system.
1. Orange
Orange is a component-based data mining and machine learning software suite, featuring friendly yet
powerful and flexible visual programmingfront-end for explorative data analysis and visualization,
and Python bindings and libraries for scripting.
2. Rapid Miner
RapidMiner, formerly YALE (Yet Another Learning Environment), is an environment for machine
learning, data mining, text mining, predictive analytics, and business analytics. It is used for research,
education, training, rapid prototyping, application development, and industrial applications. In a poll by
KDnuggets, a data-mining newspaper, RapidMiner ranked second in data mining/analytic tools used for
real projects in 2009[1] and was first in 2010.
3. Weka
The Weka workbench[1] contains a collection of visualization tools and algorithms for data analysis and
predictive modeling, together with graphical user interfaces for easy access to this functionality. The
original non-Java version of Weka was a TCL/TK front-end to (mostly third-party) modeling algorithms
implemented in other programming languages, plus data preprocessing utilities in C, and a Makefile-
based system for running machine learning experiments.
b) What are the problems that can be caused by a Computer Virus?
How can you protect you system from Computer Virus?
Answer:
A computer virus is a small software program that spreads from one computer to another computer and
that interferes with computer operation. A computer virus may corrupt or delete data on a computer, use
an e-mail program to spread the virus to other computers, or even delete everything on the hard disk.
Computer viruses are most easily spread by attachments in e-mail messages or by instant messaging
messages. Therefore, you must never open an e-mail attachment unless you know who sent the message
or unless you are expecting the e-mail attachment. Computer viruses can be disguised as attachments of
funny images, greeting cards, or audio and video files. Computer viruses also spread by using downloads
on the Internet. Computer viruses can be hidden in pirated software or in other files or programs that you
may download.
We can protect our computer from our virus using an Anti-Virus program e.g. Kaspersky Anti-Virus.
c) Why do you need an Operating system for a Computer System?
Compare and contrast the following Operating systems:
5
a. Batch Operating System versus Multi-programming Operating system
b. Network Operating System versus Distributed Operating System
Answer:
The Operating System provides abstractions for other programs to work with, like files and disks.
Without an operating system, you would have to access all of the hardware at a very low level -
implement your own file system, etc.
The operating system handles the menial jobs so that other programs can concentrate on something
useful.
a. Batch Operating System: Batch operating system is the operating system which analyzes your
i/p and groups them into batchs .That is data in each batch is of similar characteristics.And then it
performs operation on each individual batch.
Multiprogramming Operating System:
The mismatch between the speeds of input / output device and CPU leaves some resources of the
computer system under utilized. However , if the computer system is working in the multiprogramming
mode, better utilization of the available equipment can be realized multi programming refers to keeping
several programs in different parts of the main memory are the same time as shown in figure 1.8 and
executing them concurrently by the CPU.
b. Difference between Network and Distributed operating system.
Distributed operating system is one where all of computers that are connected can share in tasks that need
to be done. So you could have one or more programs that you are using that are actually running on
someone else's computer. This way your computer is not bogged down by trying to do everything itself.
A network operating system is used to describe a set up where computers are connected and can share
some resources either with each other, or a central server. They generally don't openly share all of the
workload, although the server can and does provide many services for the other computers on the
network.
d) Make a list of three operating systems (please include only one
operating system for one Software Company). List the important features
of these operating systems.
Answer:
Windows
The Windows operating system is pretty versatile, and can be installed on PCs having variable amounts of
resources. There are versions of Windows that can be installed on PCs having as little resource as 233
MHz processor and 64 MB RAM. On the other hand, the later versions can require as high resources as
Pentium 4 processors with 512 MB RAM. Thus Windows users get good choices for their operating
systems, based on the system resources they have. However, Windows operating system cannot be
installed in Macintosh computers.
However, an even greater benefit of Windows users is the user-friendliness of the operating system. The
graphical user interface is surprisingly easy to work with, and many complicated tasks on Windows can
be performed with a few clicks of a mouse only. Even a layman who has never used computers can learn
how to use Windows in relatively short time interval. Windows has the highest user base, and
correspondingly, most software vendors develop software packages, tools and utilities based on this
operating system. So, whatever task users may need to perform, chances are that they will find multiple
tools or utilities to assist them in the task.
Linux
Linux users have the benefit of having low resource requirements as well. Linux can be installed on a PC
just having the bare minimum resources. In fact, Linux is so versatile that almost any type of computer
and console can probably support it, except Macintosh computers, which come preloaded with Mac OS
X. However, the real problem with Linux mostly lies in its lack of user-friendliness. While Linux does
have a good graphical user interface, users still have to use the command line to perform many tasks.
Command lines only accept textual commands that must be typed by hand, and are often too complicated
for novice users.
Mac
Macintosh computers come preloaded with the Mac OS X, and this OS can only be installed on the Mac.
These computers are considerably more expensive than other PCs. Even an entry level Mac can cost
almost twice the amount required to assemble a Windows PC. Price is a major setback, and so is the
hardware support of this OS. Mac OS X can only work on computers built specifically for the operating
system. No other type of computer can run a Mac OS X.
These are basically the compatibility issues regarding the three major operating systems that are used
around the world these days. Each has pros and cons, and the choice is ultimately dependent on the user’s
preference.
e) Explain the following in the context of Programming Languages with the
help of an example:
4
a. Statements
b. Assignment Operation
c. Hierarchy of Operators
d. Arrays
e. Functions
f. Subroutines
Answer:
a. Statements:
Statement is a part of your program that can be executed. In other words every statement in your
program alone or in combination specifies an action to performed by your program. C provides
variety of statements to help you attain any function with maximum flexibility and efficency. One
of the reason for popularity of C is because of the extreme power provided to programmer in C
due to it rich and diverse set of statements define in C. For becoming a top notch programmer you
must have clear understanding of the C statments and the situations where staments in C are
applicable.
b. Assignment Operation:
In the C++ programming language, the assignment operator, '=', is the operator used for
assignment. Like most other operators in C++, it can be overloaded.
The copy assignment operator, often just called the "assignment operator", is a special case of
assignment operator where the source (right-hand side) and destination (left-hand side) are of the
same class type. It is one of the special member functions, which means that a default version of
it is generated automatically by the compiler if the programmer does not declare one. The default
version performs a memberwise copy, where each member is copied by its own copy assignment
operator (which may also be programmer-declared or compiler-generated).
c. Hierarchy of operators:
Operator Description Associativity
() left-to-right
Parentheses (function call) (see Note 1)
[]
Brackets (array subscript)
.
Member selection via object name
->
Member selection via pointer
++ --
Postfix increment/decrement (see Note 2)
++ -- Prefix increment/decrement right-to-left
+ - Unary plus/minus
! ~ Logical negation/bitwise complement
(type) Cast (change type)
* Dereference
& Address
sizeof Determine size in bytes
* / % Multiplication/division/modulus left-to-right
+ - Addition/subtraction left-to-right
<< >> Bitwise shift left, Bitwise shift right left-to-right
< <= Relational less than/less than or equal to left-to-right
> >= Relational greater than/greater than or equal to
== != Relational is equal to/is not equal to left-to-right
& Bitwise AND left-to-right
^ Bitwise exclusive OR left-to-right
| Bitwise inclusive OR left-to-right
&& Logical AND left-to-right
|| Logical OR left-to-right
?: Ternary conditional right-to-left
= Assignment right-to-left
+= -= Addition/subtraction assignment
*= /= Multiplication/division assignment
%= &= Modulus/bitwise AND assignment
^= |= Bitwise exclusive/inclusive OR assignment
<<= >>= Bitwise shift left/right assignment
, Comma (separate expressions) left-to-right
d. Arrays:
An array in C Programing Language can be defined as number of memory locations, each of
which can store the same data type and which can be references through the same variable name.
An array is a collective name given to a group of similar quantities. These similar quantities could
be percentage marks of 100 students, number of chairs in home, or salaries of 300 employees or
ages of 25 students.
e. Functions:
A function is a block of code that has a name and it has a property that it is reusable i.e. it can be
executed from as many different points in a C Program as required.
f. Subroutines:
A subroutine (also called procedure, function, routine, method, or subprogram) is a portion of
code within a larger program that performs a specific task and is relatively independent of the
remaining code.
f) Compare and contrast the functions of a Compiler and Interpreter.
Answer:
Compiler
1 : one that compiles
2 : a computer program that translates an entire set of instructions written in a higher-level
symbolic language (as C) into machine language before the instructions can be executed
spends a lot of time analyzing and processing the program
the resulting executable is some form of machine- specific binary code
the computer hardware interprets (executes) the resulting code
program execution is fast
Interpreter
1: one that interprets: as a: one who translates orally for parties conversing in different languages
b: one who explains or expounds
2 a: a machine that prints on punch cards the symbols recorded in them by perforations b: a
computer program that executes each of a set of high-level instructions before going to the next
instruction
relatively little time is spent analyzing and processing the program
the resulting code is some sort of intermediate code
the resulting code is interpreted by another program
program execution is relatively slow
g) List at least five features of the following application software. Also give
names of at least 2-3 popular software that are used for that application.
3
a. Project Management Software
b. Spreadsheet
c. Database Management System
a. Project Management Software
i. Project dashboard
ii. Project planner
iii. Time tracking
iv. Expense Tracking
v. Online Storage
vi. E.g. 24sevenoffice
b. Spreadsheet
i. Formulae
ii. Charts
iii. Formatting
iv. Cell locking
v. Integration of images and web
vi. E.g. MS Excel
c. Database Management software
i. Table
ii. Form
iii. Report
iv. Macro
v. Data Access page
vi. E.g. MS Access
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