Class 10 Computer Science Solution
NETWORK AND TELE COMMUNICATION
a. Telecommunication is a system if transmission of sounds, images, texts or data in the form of electronic signals.
b. Modes for transmitting data from one device to another are Simple, Half-duplex, and full duplex mode.
c. Bandwidth is measured in bits per second.
d. Cat 5 cable is used with RJ-45 connector.
e. Microwave is a wireless technology that can be used to transmit data between two different computers.
f. MODEM is short form of Modulator-Demodulator.
g. Linux is an example of network operating system.
h. Peer-Peer network is group of computers, which acts as server and workstation.
WAN = Wide Area Network
MAN = Metropolitan Area Network
UTP = Unshielded Twisted Pair
STP = Shielded Twisted Pair
POP = Post Office Protocol
NIC = Network Interface Card
HTTP = Hyper Text Transfer Protocol
MODEM = Modulator Demodulator
SMA = Shape Memory Alloy
BNC = Baby N Connector
Protocol ---------------> Rules to exchange data
LAN ---------------> Network within a building
MAN ---------------> Network within a city
Coaxial ---------------> BNC
Cat 5 ---------------> RJ-45
Hub ---------------> Central device for star topology
a. Data communication system is the collection of hardware, software and other devices that allows exchanging data, information and voice between two or more devices through a wire or radio waves.
The components of data communication are as follows:
Data: This is the data that is to be communicated.
Sender: This is the device used to send data.
Medium: This is the device through which the sender makes communication to the receiver.
Receiver: This is the device which receives data sent by the sender.
Protocol: This is the set of rules that are followed nu the sender and the receiver to make communication possible.
b. The differences between simplex and duplex modes in communication are as follows:
In this mode, the transmission can take place in only one direction.
In this mode, data can be transmitted in both direction but only to one direction at a time.
Examples: TV broadcasting, Radio transmission etc.
Example: Wireless, handset and walky-talky.
c. Differentiate between bridge and router is given below:
It is a device that connects two or more similar types of networks.
It is a device that connects two different networks.
It does not use the address for filtering and forwarding the data.
It uses the address for filtering and forwarding the data.
d. A computer network is a logical or physical interconnection between two or more computers such that they could communicate with each other.
The advantages of computer network are as follows:
i. A computer networked environment allows faster, easier and reliable transfer of data files from one computer to another.
ii. A network computer allows sharing of networked connected peripherals and simultaneous access to programs and data irrespective of the physical location of the resources and the user.
iii. Computers in network can access the network connected hardware devices like printer, scanner, disk drives etc.
e. The three models of network are as follows:
i. Client - Server Network
ii. Peer - to - Peer Network
iii. Centralized Computing Network
i. Client Server Network
It is a type of network in which each computer in a network is either a client or a server. It is an arrangement where some programs, files or other resources located on one computer called the server but are available to other systems on the network, called clients.
f. Protocols are the sets of rules that the computer on the network must follow to communicate and to exchange the data with each other.
The names of the protocols are as follows:
FTP = File Transfer Protocol
SMTP = Simple Mail Transfer Protocol
TCP/IP = Transmission Control Protocol/ Internet Protocol
ARP = Address Resolution Protocol
POP = Post Office Protocol
HTTP = Hyper Text Transfer Protocol
CDP = Cisco Discovery Protocol
g. Each computer on any types of network needs a hardware component to control the flow of data. The device that performs this function is Network Interface Card (NIC), commonly called network card.
h. A network topology refers to the shape of the network in which all the computers are connected together.
Star topology is a network topology where each individual piece if network is attached to a central node. The attachment of these network pieces to the central component is visually represented in a dorm similar to a star.
i. The advantages and disadvantages of bus topology are as follows:
i. It is easy to set up and extend bus network.
ii. Cable length required for this topology is the least compared to other networks.
iii. Bus topology costs very less.
iv. It is mostly used in small networks. It is good for LAN.
i. It is not suitable for networks with heavy traffics.
ii. It is difficult to detect and troubleshoot fault at individual station.
iii. There is limit on central cable length and number of nodes that can be connected.
iv. Security is very lows because the entire computer receives the sent signals from the source.
Local Area Network
A Local Area Network (LAN) is a network of computers that are relatively near to each other and are connected in a war that enables them to communicate by a cable and a small wireless device. A LAN consists of just two or three computers to exchange data or share resources or it can include hundreds of computers of different kinds.
Metropolitan Area Network
Metropolitan Area Networks (MANs) are large computers networks spread over a city or neighboring cities. A MAN can have a group of many LANs. Especially, big companies, banks, offices etc. have their branches or sub offices in a city or in neighboring cities. They use MAN to connect with their branches or sub offices for communicating data and information. The communication media in MANs may be optical fiber or unbounded communication media like microwave system, infrared system, radiowave to link their branches and sub offices.
Wide Area Network
Wide Area Network is a telecommunications network usually used for connecting computers that spans a wide geographical area. WANs can be used to connect cities, states or even computers. Typically, it will employ communication circuits such as long distance telephone wires, microwaves and satellites. WANs are often used by larger corporations or organizations to facilitate the exchange of data. The world's most popular WAN is the Internet.
k. Difference between LAN and WAN are as follows:
l. The advantages and disadvantages of star topology are as follows:
i. As compared to bus topology, it gives far much better performance.
ii. Easy to connect new nodes or devices. In star topology new nodes can be added easily without affecting rest of the network.
iii. Centralized management. It helps in monitoring the network.
iv. Failure of one node or link does not affect the rest of network. At the same time it is easy to detect and troubleshoot it.
i. Too much dependency on central devices. If it falls whole network goes down.
ii. The use of hub, router or a switch as central devices increases the overall cost of the network.
iii. Performance and as well number of nodes which can be added in such topology is depended in capacity of central devices.
MODEM stands for Modulator Demodulator. It is the device that converts digital data to analog form and vice versa. It is a device used to transfer the data of one computer to another using telephone lines.
The signals transmitted become weak due to some problem in the transmission mediums or the distance between the two locations. A repeater is a device that amplifies the incoming signals, creates a new copy of it and transmits the signals on the network. Repeaters are required in the network where computers are a part of each other.
A hub is a hardware device that relays communication data. A hub sends data packets to all devices on a network, regardless of any MAC addresses contained in the data pocket. It is a device with multiple ports that allows network devices to be connected together. It acts as a central networking device in the star topology.
A bus topology is a network topology in which nodes are connected in a daisy chain by a linear sequence of buses. It is an arrangement of computers on a local area network in which each computer is connected to a central cable through which data is channeled.
Ring topology is a network topology in which each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring. Data travel from node to node with each node along the way handling every packet
c. None of them
e. Fiber Optics
i. Both of them
j. Simplex Mode
d. Half Duplex Mode
e. Full Duplex Mode
g. Guided Media
h. Unguided Media
i. Computer Network