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Computer Science- CBSE CLASS XII

Q .1.a) Mr. Abhinav wants to implements a network using less cable length and data should be transmitted in one direction only. Name the topology and direction of data transmission.

For - 2 Marks

Ans: Ring/Circular Topology and Anti-Clock wise

b) Explain the uses of the following devices in networking-       For - 2 Marks

Ans: i) Switch: A switch is responsible for filtering data in a specific way and for forwarding packets between LAN segments.

�c) What do you mean by Communication Channel? Name any two.      For - 2 Marks

Ans: Transmission Media (Communication Channels): The cable that connects two or more nodes is the communication channels. It can be categories in two types- Guided (Wired Technology) & Unguided (Wireless Technology). Eg. Twisted Pair Cable (Ethernet Cable), Coaxial Cable, Optical Fibers, Microwave, Radio Wave, Satellite, Infrared, Bluetooth

d) Ms. Kiran has downloaded software from internet. It can be distributed and freely used by any one. Source code is not available. Name the software downloaded by her.      For - 1 Marks

Ans: Freeware

e) Write any two preventive measures for network security.      For - 1 Marks

Ans : Preventive Measures for network security-(any two)
• Implement proper security policy for your organization
• Use proper file access permissions when sharing files on Internet
•Disconnect from the Internet when away

f) Write any two advantages of open standard.      For - 1 Marks

Ans: Advantages of Open Standards-(any two)
a) Making the data accessible to all
b) Application and platform independent
c) No hidden information
d ) Diversity and interoperability in the industry
e) Offers diverse choice for users

g) Differentiate between Phonetic Text Entry and Key map based Entry of Indian language text.      For - 1 Marks

Ans: Phonetic Text Entry (Transliteration): In this type of text entry, traditional keyboards with English keys are used. But while typing, the Indian alphabets are written phonetically (i.e., the way they sound as per the pronunciation) in English Script and then converted to corresponding language word. For e.g. we will type "mera desh mahaan" from English keyboard and the relevant phonetic key entry software will transliterate it in the language selected eg. Hindi.("esjk ns'k egku")
Keymap based Entry: In this method the keyboard keys are mapped to specific characters using a keymap. The whole arrangement of mapping the keyboard keys to specific language characters is known as keymap.

Prepared By: Mr. Vinay Kumar Srivastava
mail to: [email protected]