CBSE Guess > Papers > Important Questions > Class XII > 2012 > Computer Science > Computer Science Mr. Pradumna Singh
Computer Science- CBSE CLASS XII
Q. 25. What is the difference between packet & message switching? For - 1 Marks
Ans.: Packet Switching: It refers to protocols in which messages are broken up into small packets before they are sent. Each packet is transmitted individually across the net. Each packet has header information which enables to route the packet to its destination. At the destination the packets are reassembled into the original message.
Message Switching: In this technique, first the source computer transfers data to the buffer of switching office computer. Further it looks for a free link to another switching office, and then the data are transferred to this link.Q. 26. Expand the following terminologies : For - 1 Marks
i) PHP ii) SMSC
Ans.: i) PHP – Hypertext Preprocessor ii) SMSC – Short Message Service Center
Q. 27. What is infrared technology? For - 1 Marks
Ans.: INFRARED : Infrared technology allows computing devices to communicate via short-range wireless signals. The infrared transmission technology used in computers is similar to that used in consumer product remote control units. This ray transmits digital data bi-directionally through the air and can propagate throughout a room, but will not penetrate walls.Q. 28. What do you mean by spam? For - 1 Marks
Ans.: SPAM :- It refers to electronic junk mail or junk newsgroup postings. Some people define it as any unsolicited e-mail.
Q. 29. What is proprietary software?. For - 1 Marks
Ans.: Proprietary software: It refers to any computer software that has restrictions on any combination of the usage, modification, copying or distributing modified versions of the software. Proprietary software usually can be distributed at no cost or for a fee. Proprietary software may also be called closed-source software. In other words it is neither open nor freely available.
Q. 30. What is Web Hosting? For - 1 Marks
Ans.: Web hosting: It is a way of hosting web-server application on a computer system through which electronic content on the internet is readily available to any web-browser client.
Q. 31. The Rangoli Creation has set up its new center at Patna for its office & web based activities. It has four blocks of buildings as shown in the diagram below:
The distance between various blocks are :
Block A to Block B |
30 m |
Block B to Block C |
110 m |
Block C to Block D |
55 m |
Block A to Block D |
260 m |
Block B to Block D |
195 m |
Block A to Block C |
32 m |
Number of computers in each block are :
Block A |
25 |
Block B |
55 |
Block C |
125 |
Block D |
15 |
( A ) . Suggest the cable layout (with diagram) of connections among the blocks & technology. For - 1 Marks
Ans. : (Draw any one)
( B ) . Suggest the most suitable place to house the server, with a suitable reason. For - 1 Marks
Ans.: The most suitable place to house the server would be Block C as it has the maximum number of computers.
( C ) . Suggest the placement of the following devices with reasons : For - 1 Marks
i) Repeater ii) Switch/Hub
Ans.: i) In layout 1 repeater will be placed between C & B blocks
OR
In layout 2, repeater will be placed between C & B and between B & D blocks
ii) Switch/Hub will be placed in all the blocks as they have their own computer networks.
( D ) The organization is planning to link its another office in the city located in the hilly region where cable connection is not feasible. Suggest an economic way to connect it with reasonably high speed. Justify your answer. For - 1 Marks
Ans.: Radio Wave would be an economic way to connect it with reasonably high speed. It offers mobility & freedom from land acquisition rights that are required for laying, repairing cables.
Prepared By: Mr. Pradumna Singh
mail to: [email protected]
