Page 224 - PYTHON-12

SOLVED QUESTIONS
1. Define a network. What is its need?
Ans. A network is an interconnected collection of autonomous computers that can share and exchange
information.
Need for networking:
(a) Resource sharing: Resources are shared by all computers over the network for effective utilization.
(b) File sharing: A file in a network can be accessed from anywhere.
2. Write two advantages and two disadvantages of network.
Ans. Advantages of network:
(a) We can share resources such as printers and scanners.
(b) We can share data and access files from any computer.
Disadvantages of network:
(a) If there is any problem in the server, then no communication can take place.
(b) Network faults can cause loss of data.
(c) If there is no privacy mechanism used then the entire network can be accessed by an unauthorized
person.
3. What is ARPANET? What is NSFNET?
Ans. ARPANET (Advanced Research Project Agency Network) is a project sponsored by US Department of Defence.
NSFNET was developed by the National Science Foundation which was a high capacity network and strictly
used for academic and engineering research.
4. What are the various types of networks?
Ans. A network is an interconnection of several nodes through some communication media with the goal of
sharing data, files and resources. There are three types of networks:
(a) Local Area Network (LAN)
(b) Metropolitan Area Network (MAN)
(c) Wide Area Networks (WAN)
5. Name the various layers of coaxial cable.
Ans. Coaxial cable consists of the following layers:
(a) A metallic rod-shaped inner conductor.
(b) An insulator covering the rod.
(c) A metallic outer conductor called shield.
(d) An insulator covering the shield.
(e) A plastic cover.
6. What is a spam mail? [CBSE D 2015]
Ans. Spam is the abuse of electronic messaging systems (including most broadcast media, digital delivery
systems) to send unsolicited bulk messages indiscriminately.
7. Differentiate between FTP and HTTP. [CBSE D 2015]
Ans. FTP is a protocol to transfer files over the internet. HTTP is a protocol which allows the use of HTML to
browse web pages in the World Wide Web. [CBSE D 2015]
Computer Science with Python–XII 8.70 9. What is a worm? How is it removed? [CBSE D 2015]
8. Out of the following, which is the fastest (a) Wired, and (b) Wireless medium of communication? Infrared,
Coaxial Cable, Ethernet Cable, Microwave, Optical Fibre.
Ans. (a) Wired: Optical Fibre
(b) Wireless: Infrared or Microwave

Ans. A worm is a self-replicating computer program. It uses a network to send copies of itself to other computers
on the network and it may do so without any user intervention. Most of the common antivirus (anti-
worm) software remove worm.