O Level M2 R4 Solved Jan 2020 (Long Questions)

5(A)Website Development Timeline When you think of building a website, your thoughts rotate around two main issues – price and time. These two values depend largely on the size and scope of the project. To outline the whole development process, you can create a website development timeline, adding tasks, and establishing milestones for your project. It is the best way to track your project implementation to make sure you keep up with the deadline. The Web Site Design and Development Process There are numerous steps in the web site design and development process. From gathering initial information, to the creation of your web site, and finally to maintenance to keep your web site up to date and current. 
The exact process will vary slightly from designer to designer, but the basics are the same. 
1. Information Gathering 
2. Planning 
3. Design 
4. Development
5. Testing and Delivery 
6. Maintenance

5(B)
<div style="text-align:center;">
<!--Rows Starts with 2 Frames--->

<div style=" background:dodgerblue;height:50%;">
<div style="width:50%;float:left;background:yellow;height:100%;">Column1</div>
<div style="width:50%;float:left;background:green;height:100%;">Column2</div>

</div>

<div style=" background:tomato;height:50%;position:relative;margin-top:-20px;">
<h1>Frame 2</h1>

</div>

</div>

5(c) Java as an Internet Language java is an object oriented language and a very simple language. Because it has no space for complexities. At the initial stages of its development it was called as OAK. OAK was designed for handling set up boxes and devices. But later new features were added to it and it was renamed as Java. Java became a general purpose language that had many features to support it as the internet language. Few of the features that favors it to be an internet language are: Cross Platform Compatibility: The java source files (java files with .java extension) after compilation generates the bytecode (the files with .class extension) which is further converted into the machine code by the interpreter. The byte code once generated can execute on any machine having a JVM. Every operating system has it's unique Java Virtual Machine (JVM) and the Java Runtime Environment (JRE). 
Support to Internet Protocols: Java has a rich variety of classes that abstracts the Internet protocols like HTTP , FTP, IP, TCP-IP, SMTP, DNS etc .
 Support to HTML: Most of the programming languages that are used for web application uses the html pages as a view to interact with the user. Java programming language provide it's support to html. For example. Recently the extension package jipxhtml is developed in java to parse and create the html 4.0 documents
 Support to Java Reflection APIs: To map the functionalities, Java Reflection APIs provides the mechanism to retrieve the values from respective fields and accordingly creates the java objects. These objects enables to invoke methods to achieve the desired functionality.

6(A)

Website A site or website is a central location of web pages that are related and accessed by visiting the home page of the website using a browser. For example, the Computer Hope website address URL (Uniform Resource Locator) is https://www.computerhope.com.
Web page : A web page or webpage is a document commonly written in HTML (Hypertext Markup Language) that is accessible through the Internet or other networks using an Internet browser. A web page is accessed by entering a URL address and may contain text, graphics, and hyperlinks to other web pages and files.
Web Server Web server is a computer where the web content is stored. Basically web server is used to host the web sites but there exists other web servers also such as gaming, storage, FTP, email etc.
URL Also known as a web address, a URL (Uniform Resource Locator) is a form of URI and a standardized naming convention for addressing documents accessible over the Internet and Intranet. An example of a URL is https://www.computerhope.com, which is the URL for the Computer Hope website.
HOME PAGE A home page is the default or front page of a site. It is the first page that visitors see when they load a URL. Web managers can control the home page as a way of directing the user experience.

6.(B)

The web browser is an application program that displays a www document. It usually uses other internet services to access the document. Web server is a program or a computer that can provide services to other programs called clients.
The main difference between a Web browser and a Web server is that Web browser requests for the document and services, and act as an interface between a client and a server which displays the web content. On the other hand, Web server accepts, approve, and response to the request made by a web browser for a web document.

WEB SERVER WORKING

A web server processes incoming network requests over HTTP and several other related protocols. The primary function of a web server is to store, process and deliver web pages to clients. The communication between client and server takes place using the Hypertext Transfer Protocol (HTTP)

7(A) 

TCP/IP Model

• The TCP/IP model was developed prior to the OSI model.
• The TCP/IP model is not exactly similar to the OSI model.
• The TCP/IP model consists of five layers: the application layer, transport layer, network layer, data link layer and physical layer.
• The first four layers provide physical standards, network interface, internetworking, and transport functions that correspond to the first four layers of the OSI model and these four layers are represented in TCP/IP model by a single layer called the application layer.
• TCP/IP is a hierarchical protocol made up of interactive modules, and each of them provides specific functionality.

                                            Protocols By Layer

                         Devices on each layer

1. Physical Layer – Hubs Cables Repeaters 

2. Data Link Layer - Bridges Modem Network Interface Card 

3. Network Layer – Routers Brouters 

4. Transport Layer –  Gateways Firewall 

5. Application Layer - Computer, Phones, Servers Gateways and Firewalls

                       Data Unit On Each Layer

The data unit created at the application layer is called a message, at the transport layer the data unit created is called either a segment or an user datagram, at the network layer the data unit created is called the datagram, at the data link layer the datagram is encapsulated in to a frame and finally transmitted as signals along the transmission media.

7.(B) 

Cryptography is the science of secret writing with the intention of keeping the data secret. Cryptography is classified into symmetric cryptography, asymmetric cryptography and hashing.

 Private Key: In Private key, the same key (secret key) is used for encryption and decryption. In this key is symmetric because the only key is copy or share by another party to decrypt the cipher text. It is faster than the public key cryptography.

 Public Key: In Public key, two keys are used one key is used for encryption and another key is used for decryption. One key (public key) is used for encrypt the plain text to convert it into cipher text and another key (private key) is used bu receiver to decrypt the cipher text to read the message.

7.(c) 

The arrangement of a network which comprises of nodes and connecting lines via sender and receiver is referred as network topology. The various network topologies are :

BUS Topology

Bus topology is a network type in which every computer and network device is connected to single cable. When it has exactly two endpoints, then it is called Linear Bus topology

RING Topology

It is called ring topology because it forms a ring as each computer is connected to another computer, with the last one connected to the first. Exactly two neighbours for each device.

STAR Topology

In this type of topology all the computers are connected to a single hub through a cable. This hub is the central node and all others nodes are connected to the central node.

MESH Topology

It is a point-to-point connection to other nodes or devices. All the network nodes are connected to each other. Mesh has n(n-1)/2 physical channels to link n devices.

There are two techniques to transmit data over the Mesh topology, they are :

1. Routing
2. Flooding

MESH Topology: Routing

In routing, the nodes have a routing logic, as per the network requirements. Like routing logic to direct the data to reach the destination using the shortest distance. Or, routing logic which has information about the broken links, and it avoids those node etc. We can even have routing logic, to re-configure the failed nodes.

MESH Topology: Flooding

In flooding, the same data is transmitted to all the network nodes, hence no routing logic is required. The network is robust, and the its very unlikely to lose the data. But it leads to unwanted load over the network.

8(A) The main difference between Applet and Application is that the applet is a small java program that can be executed by a Java-compatible web browser while the application is a standalone program that can directly run on the machine. ... It is a small program and does not affect the operating system or the hardware

8(B)

<span style="display:none;" id="name">Only 20 Charcters are allowed</span>

<span style="display:none;" id="num">Only 0-9 Digit Valid</span>

<form name="myform" id="myform">

<input type="text" name="name" autofocus="true"  required placeholder="Name" >

<input type="tel" name="mobile" autofocus="true"  required placeholder="Mobile">

<button name="btn" onclick="validData()">Submit</button>

</form>

<script>

function validData()

{

var a = document.myform.mobile;

var sname = document.myform.name;

var name=document.getElementById("name");

var num=document.getElementById("num");

var btn = document.myform.btn;

var b =/(>|&|<|[a-zA-Z])/;

if(sname.value.length>20){

alert("Only 20 Characters Allowed");

document.getElementById("myform").reset();

}

if(b.test(a.value))

{

alert("0-9 digits allowed");

document.getElementById("myform").reset();

}

}

</script>

9.(A)

Client-side Scripting

The client-side environment used to run scripts is usually a browser. The processing takes place on the end users computer. The source code is transferred from the web server to the users computer over the internet and run directly in the browser.[2]

The scripting language needs to be enabled on the client computer. Sometimes if a user is conscious of security risks they may switch the scripting facility off. When this is the case a message usually pops up to alert the user when script is attempting to run.

Server Side Scripting 

A server is a computer system that serves as a central repository of data and programs and is shared by clients

The server-side environment that runs a scripting language is a web server. A user's request is fulfilled by running a script directly on the web server to generate dynamic HTML pages. This HTML is then sent to the client browser. It is usually used to provide interactive web sites that interface to databases or other data stores on the server.

This is different from client-side scripting where scripts are run by the viewing web browser, usually in JavaScript. The primary advantage to server-side scripting is the ability to highly customize the response based on the user's requirements, access rights, or queries into data stores.

9(B)Abstract class in Java is similar to interface except that it can contain default method implementation. An abstract class can have an abstract method without body and it can have methods with implementation also.

abstract keyword is used to create a abstract class and method. Abstract class in java can’t be instantiated. An abstract class is mostly used to provide a base for subclasses to extend and implement the abstract methods and override or use the implemented methods in abstract class.

(c) 

What is JavaScript?

JavaScript is an object-oriented scripting language which allows you to create dynamic HTML pages with interactive effects within a webpage. JavaScript was available in the browser until Google chrome released its JavaScript engine as “node.js”. JavaScript allows you to process and maintain data within the browser. We able to use JavaScript across full stack development with help of node.js which helps frontend developers to handle backend logic and application programming interface without learning a new programming language. JavaScript was created by Brendan Eich at Netscape which came into existence in 1995. It runs on web-browser only and it is an interpreted programming language. JavaScript allows client-side scripts to interact with the users, communicate asynchronously, control the browsers and alter the web page content which is displayed can be achieved through JavaScript

What is VBScript?

VBScript is a general scripting language developed on visual basic and developed by Microsoft. It is also called as an active scripting language. It is a visual basic edition scripting language as it is developed (modeled) based on visual basic to be a lightweight scripting language with a fast interpreter. VBScript is supported only by browser Internet Explorer and it is mostly used in Microsoft environments and visual basic language products. It will be installed by default in every windows desktop version. VBScript can be executed through windows script host and can be embedded through Microsoft script control. VBScript uses a common object model to access the environment variables, File system objects used for reading, writing, update, delete operations and it is a general scripting language. VBScript is mostly used by system administrators, test automation scripting language for different tools such as QTP. VBScript is an easy scripting language to learn.

(d) 

Session Bean

Session bean encapsulates business logic only, it can be invoked by local, remote and webservice client.

It can be used for calculations, database access etc.

The life cycle of session bean is maintained by the application server

There are 3 types of session bean. 1) Stateless Session Bean: It doesn't maintain state of a client between multiple method calls. 2) Stateful Session Bean: It maintains state of a client across multiple requests. 3) Singleton Session Bean: One instance per application, it is shared between clients and supports concurrent access (E)The Domain Name System (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.