Write down HTML and JavaScript code for the following requirements:
Declare an Array with the identifier SUBJECT having length 5. Assign following values to the array elements:
MIS, Java, Algorithms, Databases, C++
Show all values in reverse order.
Question No: 41 ( M - 10 )
How instant messaging works? Write the steps involved in this process.
The Instant Messaging services available allow us to maintain a list of people (contacts) that we interact with regularly. We can send instant messages to any of the contacts in our list as long as that contact is online.
Following steps are involved in IM working:
1. User commences the IM client.
2. IM client finds the IM server & logs in.
3. It launches communication info (IP address, etc) to the IM server.
4. IM server finds user’s contacts & sends him/her the communication info.
5. IM server also notifies the contacts that the user is online; sends his/her communication info to them.
6. The user’s & the contact’s IM clients are ready to communicate directly (P2P).
7. As new contact has come online, IM server informs them about the user being online & vice versa.
8. Multiple, real-time chat are possible.
9. When the user logs-off, his/her IM client informs the IM server.
10. IM server wipes away the temporary file and informs the user’s contact’s about his/her ‘offline’ status.
Question No: 5 ( M - 10 )
What kind of operations takes place inside Microprocessors Building Blocks? Enlist them with brief description.
Bus Interface Unit: The bus interface unit is the part of the processor that interfaces with the rest of the PC. Its name comes from the fact that it deals with moving information over the processor data bus.
Instruction Decoder: The instruction decoder of a processor is a combinatorial circuit sometimes in the form of a read-only memory, sometimes in the form of an ordinary combinatorial circuit.
Arithmetic & Logic Unit (ALU): An arithmetic and logical unit (ALU) also known as “Integer Unit” is one of the core components of all central processing units. It is capable of calculating the results of a wide variety of common computations.
Floating-Point Unit (FPU): A floating point unit (FPU) is a part of a CPU specially designed to carry out operations on floating point numbers.
Registers: A register is a device for storing data. It is a small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values.
Control Unit: A control unit is the part of a CPU or other device that directs its operation. The outputs of the unit control the activity of the rest of the device.
Instruction Set: This is the set of machine instructions that a microprocessor recognizes and can execute. It is the only language microprocessor knows.
Question No: 7 ( M - 8 )
a) Differentiate between SMTP and POP3 server. (3 marks)
SMTP (Simple Mail Transfer Protocol) is a protocol used to send and receive eMail messages over a TCP/IP network. Whereas POP3 (Post Office Protocol) is a protocol used for receiving eMail messages. A POP3 server maintains text files (one file per user accounts) containing all messages received by a user. eMail client interacts with the POP3 server for discovering and downloading new eMail messages.
b) How can you justify that a DBMS is better to use than Flat-file database? (5 marks)
A DBMS takes care of the storage, retrieval, and management of large data sets on a Database. It provides SW tools needed to organize & manipulate that data in a flexible manner.
Whereas in Flat-file database the text file format makes it hard to search for specific information or to create reports that include only certain fields from each record.
Question No: 8 ( M - 8 )
What will be the output of this programme? Write comments where you find “//” symbol in the following code.
<html>
<head>
<script language="JavaScript">
function doSomething() { // 1
setTimeout('doSomething()',10000); // 2
}
</script>
</head>
<body onLoad="doSomething()"> // 3
document.write(“Virtual University of Pakistan”);
</body>
</html>
// 3 document.write(“Virtual University of Pakistan”);
Question No: 9 ( M - 8 )
a) How Trojan Horses and Worms affect a computer system? What guidelines should be adopted to troubleshoot with malicious software? (6 marks)
Trojan horses are stand-alone programs. The look like what they are not and appear to be something interesting and harmless (e.g. a game) there execution results in destruction. Worms only make copies of themselves on the infected computer.
Following guidelines should be adopted to troubleshoot with malicious software:
• Download SW from trusted sites only.
• Do not open attachments of unsolicited eMails.
• Use floppy disks and CDROMs that have been used in trusted computers only.
• When transferring files from your computer to another, use the write-protection notches.
• Stay away from pirated SW.
• Regularly back your data up.
• Install Antivirus SW; keep it and its virus definitions updated.
b) Which part of a virus consists of malicious computer instructions? (2 marks)
Payload is the part of virus that generally consists of malicious computer instructions.
Question No: 31 ( M - 1 )
What is the function of Network Interface Card?
NIC is an I/O device that plugs into the computer and it enables it to communicate over a network.
Question No: 32 (M - 1)
In programming, what is a loop?
Question No: 33 (M - 2)
What is an intelligent system?
Intelligent system is a SW programs or SW/HW systems designed to perform complex tasks employing strategies that mimic some aspect of human thought.
Question No: 34 (M - 2 )
Why hub is used in networks?
Hub is networking equipment and a device which connects several computers to form a network. In a network the NIC translates the message into electrical pulses suitable for the computer network in use & transmits it to the hub through the cable. The hub receives them and forwards them to all computers connected to it.
Question No: 35 ( M - 3 )
What are Trojan Horses?
Trojan Horses are unlike viruses, they are stand-alone programs. The look like what they are not. They appear to be something interesting and harmless (e.g. a game) but when their execution result in destruction.
Question No: 36 (M - 3)
Elaborate with examples Vector or Object oriented graphics.
Vector or Object-Oriented Graphics treats everything that is drawn as an object. Objects retain their identity after they are drawn. These objects can later be easily moved, stretched, duplicated, deleted, etc
They are resolution independent and relatively small file size.
Examples: swf, svg, wmf, ps.
Question No: 37 (M - 3)
How can you define a consistent web design? Why is it needed?
A consistent web design should be the one that achieves the result that it was designed for, that result can only be achieved by giving the user what he wants, as quickly as possible, without her/him expending much effort. One definition of usability: Let the user have what he wants, quickly, without much effort “Quickly” is important!
Question No: 39 (M - 5)
What are the advantages of multimedia presentations? Write any five.
Following are the advantages of multimedia presentations:
· Great tool for effectively communicating ideas to an audience
· All electronic
· Easy to make last minute changes
· The undo feature encourages experimentation
· More attractive; commanded more interest
· May include animations, sound, video
· Easy to catalog, store, and recall
· Great tool for making presenter-free interactive material (e.g. self-learning tutorials)
Question No: 41 (M - 10)
How virtual communities are formed? How these are different from other communities? Give examples.
Virtual Communities are interest-based communities. Members with common interest share ideas, ask questions, post answers and make announcements through mailing-lists, news groups or message boards. This is how they are formed. These communities are definitely very different from traditional ones. There are generally no bars on membership based on gender, race or religion. However, they may lack the respect for the individual and civility that are the norm within conventional, geography-based communities.
