Plus One Computer Science Chapter Wise previous Questions Chapter 11 Computer Networks

Kerala Plus One Computer Science Chapter Wise previous Questions Chapter 11 Computer Networks

Question 1.
Any device which is directly connected to a network is generally known as (March – 2015)
Answer:
Node or Work station or Client or Terminal

Question 2.
In topology, all the nodes are connected to a main cable. (Say – 2015)
Answer:
Bus topology

Question 3.
Write the full from of FTTH. (March – 2016)
Answer:
Fibre To The Home

Question 4.
Which one of the following statements is TRUE in relation with Wi-MAX Internet connectivity? (March – 2016)
a) make use of satellite connection
b) Uses cable connection
c) Uses laser beam for connection
d) Microwave is used for connectivity
Answer:
d) microwave is used for connectivity

Question 5.
Identify the type of LAN topology in which there are more than one path between nodes, (March – 2016)
a) Star
b) Ring
c) Mesh
d) Bus
Answer:
c) Mesh topology

Question 6.
a) Different networks with different protocols are connected by a device called…. (March – 2017)
i) Router
ii) Bridge
iii) Switch
iv) Gateway

b) Define Protocol
Answer:
a) iv) gateway
b) Protocol : The rules and conventions for transmitting data.

Question 7.
a) To make data transfer faster, a switch stores two different addresses of all the devices connected to it. What are they? (March – 2015)
b) There are 5 computers in your computer lab. Write short notes on any three possible methods to interconnect these computers. Draw the diagram of each method.
Answer:
a) Identification of computers over a network :
A computer gets a data packet on a network, it can identify the senders address easily. It is similar to our snails mail, each letter is stamped in sender’s post office as well as receiver’s post office.

1. Media Access Control(MAC) address : It is a unique 12 digit hexadecimal number(IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address and its permanent.

It is of the form. MM:MM:MM:SS:SS:SS.

The first MM:MM:MM contains the ID number of the adapter company and the second SS:SS:SS represents the serial number assigned to the adapter by the company.

2. Internet Protocol (IP) address : An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(2°=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.

b) Network topologies : Physical or logical arrangement of computers on a network is called structure or topology. It is the geometrical arrangement of computers in a network. The major topologies developed are star, bus, ring, tree and mesh.

1) Star Topology : A star topology has a server all other computers are connected to it. If computer A wants to transmit a message to computer B.

Then computer A first transmit the message to the server then the server retransmits the message to the computer B. That means all the messages are transmitted through the server. Advantages are add or remove workstations to a star network is easy and the failure of a workstation will not effect the other. The disadvantage is that if the server fails the entire network will fail.

2) Bus Topology : Here all the computers are attached to a single cable called bus. Here one computer transmits all other computers listen. Therefore it is called broadcast bus. The transmission from any station will travel in both the direction. The connected computers can hear the message and check whether it is for them or not.

Advantages are add or remove computer is very easy. It requires less cable length and the installation cost is less. A disadvantage is fault detection is very difficult because of no central computer.

3) Ring Topology : Here all the computers are connected in the shape of a ring and it is a closed loop. Here also there is no central computer. Here a computer transmits a message, which is tagged along with its destination computer’s address. The message travels in one direction and each node check whether the message is for them. If not, it passes to the next node.

It requires only short cable length. If a single node fails, at least a portion of the network will fail. To add a node is very difficult.

4) Hybrid Topology : It is a combination of any two or more network topologies. Tree topology and mesh topology can be considered as hybrid topology.

a) Tree Topology : The structure of a tree topology is the shape of an inverted tree with a central node and branches as nodes. It is a variation of bus topology. The data transmission takes place in the way as in bus topology. The disadvantage is that if one node fails, the entire portion will fail.

b) Mesh Topology: In this topology each node is connected to more than one node. It is just like a mesh (net). There are multiple paths between computers. If one path fails, we can transmit data through another path.

Question 8.
ABC Ltd., required to connect their computers in their company without using wires. Suggest suitable medium to connect the computers. Explain. (Say – 2015)
Answer:
Unguided Media

• Radio waves – It transmits data at different frequencies ranging from 3 KHz. to 300 GHz.
• Microwaves – Microwave signals can travel in straight line if there is any obstacle in its path, it can’t bend. So it uses tall towers instead of short one.
• Infrared waves : These waves are used for transmitting data in short distance and its frequency range is 300 GHz to 400 GHz.

Question 9.
Write notes on the following: (Say – 2016)
a) IP address
b) MAC address
c) Modem
Answer:
a) Internet Protocol (IP) address : An IP address has 4 parts numeric address. Each parts contains 8 bits. By using 8 bits we can represent a decimal number between 0 to 255(2®=256 numbers). Each part is separated by dot. A total of 4*8=32 bits used. But nowadays 128 bits are used for IP address.
b) Media Access Control(MAC) address. It is a unique 12 digit hexadecimal number(IMEI for mobile phones, it is a 15 digit decimal number) assigned to each NIC by its manufacturer. This address is known as MAC address.

It is of the form. MM:MM:MM:SS:SS:SS.

c) Modem – It is a device used to connect the computer to the internet. It converts digital signal into analog signal (modulation) and vice versa (Demodulation)

Question 10.
Compare any three types of networks based on span of geographical area. (March – 2017)
Answer:
Types of networks
The networks are classified into the following based upon the amount of geographical area that covers.

1. Personal Area Network(PAN) : It is used to connect devices situated in a small radius by using guided media or unguided media
2. Local Area Network (LAN): This is used to connect computers in a single room, rooms within a building or buildings of one location by using twisted-pair wire or coaxial cable. Here the computers can share Hardware and software. Data transfer rate is high and error rate is less, eg:-The computers connected in a school lab.
3. Metropolitan Area Network (MAN): A Metropolitan Area Network is a network spread over a city. For example a Cable TV network. MAN have lesser
4. Wide Area Network (WAN): This is used to connect computers over a large geographical area. It is a network of networks. Here the computers are connected using telephone lines or Micro Wave station or Satellites. Internet is an example for this.
5. LAN and MAN are owned by a single organization but WAN is owned by multiple organization. The error rate in data transmission is high.

In short

Plus One Computer Science Chapter Wise previous Questions