Computer Science Related Questions

1. 1. (ক) IR 4.0 বলতে কক বুঝায়? IR 4.0 এর গুরুত্বপূর্ ণউপাদানগুতলা কলখুন।
Answer:
The Fourth Industrial Revolution (IR 4.0) is the ongoing automation of traditional
manufacturing and industrial practices, using modern smart technology. Large-scale
machine to-machine communication (M2M) and the internet of things (IoT) are integrated
for increased automation, improved communication and self-monitoring, and production
of smart machines that can analyze and diagnose issues without the need for human
intervention.
Some important Elements of IR 4.0 is given below:
• Cloud Computing
• Internet of things (IoT) platforms
• Location detection technologies
• Advanced human-machine interfaces
• Big data Analysis
• Authentication and fraud detection
• Smart sensors
• Augmented reality/ wearables
• RFID Technologies
(খ) Big data বলতে কক বুঝায়? Big data এর ববকিষ্ট্যগুতলা কলখুন।
Answer:
Big Data: Big Data is also data but with a huge size. Big Data is a term used to describe
a collection of data that is huge in volume and yet growing exponentially with time. In
short such data is so large and complex that none of the traditional data management
tools are able to store it or process it efficiently.
Characteristics of Big Data
Volume: The name Big Data itself is related to a size which is enormous. 'Volume' is one
characteristic which needs to be considered while dealing with Big Data.
Variety: Variety refers to heterogeneous sources and the nature of data, both structured
and unstructured
Velocity: The term 'velocity' refers to the speed of generation of data.
Variability: This refers to the inconsistency which can be shown by the data at times,
thus hampering the process of being able to handle and manage the data effectively.

2. 2. (ক) Procedural Oriented ও Object Oriented Programming Language মতযয পার্ ণ
কয
কক ? উভয় Language এর ২টি কতর উদাহরর্ কদন।
Answer:
Procedural Oriented Programming Object Oriented Programming
In procedural programming, program is
divided into small parts called functions.
In object oriented programming, program is
divided into small parts called objects.
Procedural programming follows top
down approach.
Object oriented programming follows
bottom up approach.
There is no access specifier in procedural
programming
Object oriented programming have access
specifiers like private, public, protected
etc.
Adding new data and function is not easy. Adding new data and function is easy.
In procedural programming, overloading
is not possible.
Overloading is possible in object oriented
programming
In procedural programming, function is
more important than data.
In object oriented programming, data is
more important than function.
Examples: C, FORTRAN, Pascal,
Basic etc.
Examples: CH, Java, Python, C# etc.
(খ) Recursion কক? Recursion পদ্ধকেতে একটি Integer সংখযার Factorial কনর্ ণ
তয়র
জনয C-Language এ একটি Program কলখুন।
Answer: [See BPSC, Assistant Network Engineer, Written Exam: 2020]
3. (ক) Data transfer rate এর কভকিতে কনতনাক্ত memory/storage device গুলাতক ববিী
বর্তক কম ক্রমানুসাতর সাজান I
(i) Flash drive (ii) SSD (iii) Cache memory (iv) DVD (v) RAM (vi) Magnetic HD
Cache memory →RAM→ SSD →Flash drive →Magnetic HD →DVD
(খ) Computer network এর OSI 7-Layer গুতলা উদাহরর্সহ কলখুন।
Answer: [See Combined 4 Banks, Assistant Programmer, Written Exam: 2020 (DU)]
4. (ক) Software এর alpha -version and β – version কক?
Answer:
The a (alpha) version of a software product is a pre-release early version that is part of a
dedicated testing process. Most software products move through a multi-step process
before being released to the public. An alpha version is part of that system for developing
efficient, accurate and bug-free software programs.
A pre-release of software that is given out to a large group of users to try under real
conditions. B (Beta) versions have gone through alpha testing in-house and are generally
fairly close in look, feel and function to the final product; however, design changes often
occur as a result.
(খ) Software Requirement Specification (SRS) বলতে কক বুঝায় ? Software
Development এর বকান যাতপ SRS বেকর করা হয়? ?
A Software Requirements Specification (SRS) is a document that captures complete
description about how the system is expected to perform. It is usually signed off at the
end of requirements engineering phase.
Software Development এর “Feasibility Study” ধাপে SRS তৈরর করা হয়।

3. (গ) Unit testing, Integration testing এবং Beta testing বলতে কক বুঝায়?
Answer:
Unit Testing: Unit testing involves the testing of each unit or an individual component of
the software application. It is the first level of functional testing. The aim behind unit testing
is to validate unit components with its performance.
Integration Testing: Upon completion of unit testing, the units or modules are to be
integrated which gives raise to integration testing. The purpose of integration testing is to
verify the functional, performance and reliability between the modules that are integrated.
Beta Testing: Beta testing is a type of User Acceptance Testing among the most crucial
testing, which performed before the release of the software. Beta Testing is a type of Field
Test. This testing performs at the end of the software testing life cycle.
5. (7) Entity-Relationship (ER) Diagram বকন বযবহার করা হয়? একটি উদাহরন এর
মাদ্ধযতম বযাখযা করুন I
Answer:
Database Design: ER diagrams are used to model and design relational databases, in
terms of logic and business rules (in a logical data model) and in terms of the specific
technology to be implemented (in a physical data model.) A relational database has an
equivalent relational table and can potentially be expressed that way as needed.
Database Troubleshooting: ER diagrams are used to analyze existing databases to find
and resolve problems in logic or deployment. Drawing the diagram should reveal
where it's going wrong.
Business Information Systems: The diagrams are used to design or analyze relational
databases used in business processes. Any business process that uses fielded data
involving entities, actions and interplay can potentially benefit from a relational database.
It can streamline processes, uncover information more easily and improve results.
Business Process Re-engineering (BPR): ER diagrams help in analyzing databases
used in business process re-engineering and in modeling a new database setup.
Education: Databases are today's method of storing relational information for
educational purposes and later retrieval, so ER Diagrams can be valuable in planning
those data structures.
(খ) Relational Database Design এ Primary Key ও Foreign Key বলতে কক বুঝায়?
উদাহরর্সহ কলখুন।
Answer:
Primary Key: Primary key is a column or group of columns in a table that uniquely identify
every row in that table. The Primary Key cannot be a duplicate meaning the same value
cannot appear more than once in the table. A table cannot have more than one primary
key. It cannot contain null values. There can be more than one candidate key in relation
out of which one can be chosen as the primary key. For Example, STUD_NO, as well as
STUD_PHONE both, are candidate keys for relation STUDENT but STUD_NO can be
chosen as the primary key.
Foreign key: Foreign key is the column of a (child) table which is used to point to the
primary key of another (parent) table. In other words, if we had a table A with a primary
key X that linked to a table B where X was a field in B, then X would be a foreign key in
B. and A is parent table and B is child table.

4. 6. (ক) Wi-Fi Network সম্পতকণ সংকিপ্ত কববরর্ কদন I Wi-Fi Sensor Network এবং Ad
Hoc Network এর মতযয পার্ ণ
কয কলখুন।
Answer:
Wi-Fi is a wireless networking technology that uses radio waves to provide wireless high
speed Internet access. A common misconception is that the term Wi-Fi is short for
“wireless fidelity,” however Wi-Fi is a trademarked phrase that refers to IEEE 802.11x
standards.
Wireless Adhoc Network Wireless Sensor Network
The medium used in wireless adhoc
networks is radio waves.
The medium used in wireless sensor
networks are radio waves, infrared, optical
media.
Application independent network is
used.
Application independent network is used
It is heterogeneous in type. It is homogeneous in type.
The traffic pattern is point-to-point. The traffic pattern is any-to-any, many-to one,
many-to-few, one-to-many.
Wireless router is used as an
interconnecting device.
Application level gateway is used as an
inter-connecting device.
The data rate is high. The data rate is low.
(খ) Authentication বলতে কক বুঝায়? Two Factor Authentication কক? উদাহরর্সহ
বযাখযা করুন।
Answer:
Authentication is the process of recognizing a user's identity. It is the mechanism of
associating an incoming request with a set of identifying credentials. The credentials
provided are compared to those on a file in a database of the authorized user's
information on a local operating system or within an authentication server.
Two-factor authentication (2FA) is a method of establishing access to an online account
or computer system that requires the user to provide two different types of information.
Two-factor authentication is a combination of two of the following:
• Something we know our password
• Something we have such as a text with a code sent to our smartphone or other
device or a smartphone authenticator app
• Something we are biometrics using our fingerprint, face or retina
Example of Two-Factor Authentication (2FA)
Apple account holders can use 2FA to ensure that accounts can only be accessed from
trusted devices. If a user tries to log in to their iCloud account from a different computer,
the user will need the password, but also a multi-digit code that Apple will send to one of
the user's devices, such as their iPhone.

5. 7. (ক) Cloud Computing এর সাকভণসগুতলা কলখুন।
Answer: Services of cloud computing:
• IaaS- Infrastructure as a Service
• PaaS- Platform as a Service
• SaaS- Software as a Service
• NaaS- Network as a Service
• CuaS-Cloud user as a Service
(খ) Algorithm কক? Algorithm প্রকাতির কেনটি পদ্ধকের নাম কলখুন।
Answer: An algorithm is a sequence of finite number of logical steps to solve a particular
problem or algorithm is an ordered set of unambiguous logical steps that produces a
result and terminates in a finite time.
Algorithm প্রকাতির কেনটি পদ্ধকের নাম:
• Flow charts
• Pseudo code
• Programming languages
(গ) Universal logic gate কক ? 3-input 17 এর একটি Universal logic gate এর Logic
symbol 47 এবং Truth Table বদখান।
Answer:
Universal Gate: A universal logic gate is a logic gate that can be used to construct all
other logic gates. The NAND and NOR gates are universal gates because any Boolean
function can be implemented using one of these gates.
3-input NAND gate Logic symbol:
3-input Universal logic gate NAND Truth Table is given below:
Input Output
A B C Y= ABC
0 0 0 1
0 0 1 1
0 1 0 1
0 1 1 1
1 0 0 1
1 0 1 1
1 1 0 1
1 1 1 0

6. 8. (ক) বকান প্রকেষ্ঠাতনর Web page development এ HTML এবং CSS এর ভূকমকা কক?
শুযুমাত্র HTML এবং CSS বযবহার কতর বকান যরতনর Web Page Development করা
বেতে পাতর?
Answer:
HTML (Hypertext Markup Language) and CSS (Cascading Style Sheets) are two of the
core technologies for building Web pages. HTML provides the structure of the page, CSS
the (visual and aural) layout, for a variety of devices. Along with graphics and scripting,
HTML and CSS are the basis of building Web pages and Web Applications.
শুধুমাত্র HTML এবং CSS বযবহার কপর Static Web Page Development করা যেপৈ োপর।
Static web pages are created using only HTML and CSS. Static web pages are only used
when the information is no more required to be modified.
(খ) PHP কক? Web Development এ Java Script এর প্রতয়াজনীয়ো সম্পতকণ কববরর্ কদন।
Answer:
PHP is a server side scripting language. that is used to develop Static websites or
Dynamic websites or Web applications. PHP stands for Hypertext Pre-processor, that
earlier stood for Personal Home Pages.
JavaScript is a client-side programming language which helps web developer to do
Web Application Development and make dynamic and interactive web pages by
implementing custom client-side scripts.
Speed: Client-side JavaScript is very fast because it can be run immediately within the
client side browser. Unless outside resources are required, JavaScript is unhindered by
network calls to a backend server.
Simplicity: JavaScript is relatively simple to learn and implement.
Popularity: JavaScript is used everywhere on the web.
Interoperability: JavaScript plays nicely with other languages and can be used in a huge
variety of applications.
Server Load: Being client-side reduces the demand on the website.