Exercise –
A. Tick the correct option –
1. A network in which two or more computers are connected
within a small area such as a room is called
LAN
2. A network which is organised around a person is known as
PAN
3. A computer which provides services to the clients and
controls access to hardware, software and other resources is known as
Server
4. In which year were twisted pair cables invented?
1881
5. Coaxial cables were invented in
1880
6. The network topology which combines the characteristics
of bus and star topologies is
Tree
B. Fill in the blanks –
| 1. In bus topology, all computers are connected by cables to central device called hub or switch. | F |
| 2. In Mesh topology, every computer is connected to every other computer on the network. | T |
| 3. There are two general levels of network security. | T |
| 4. The optical fibre cable consists of a central glass core surrounded by several layers of protective materials. | T |
| 5. Bluetooth technology was invented in 1998. | F |
| 6. STP cable is the most commonly used cable in computer networking. | F |
D. Differentiate between –
1. LAN and MAN networks –
In LAN two or more computers and
peripheral devices are connected within a small area such as room, an office
building, etc. In LAN computer terminals are physically connected with wires. A MAN is a network which covers more area than a LAN. It spreads across a city
that is why it is called Metropolitan area network. Cable TV, Telephone
Networks, etc. are some common example of MAN.
2. Mesh and Tree Topology –
In Mesh Topology every computer is
connected to every other computer on the network. Computers can be connected by
two methods Full Mesh topology and Partial Mesh topology. Mesh topology is most
expensive topology. Tree topology network combines the characteristic of bus
and star topology. Groups of star topology networks are formed which are
connected to bus backbone cable.
3. Hub and Switch –
Hub is a device used to connect
two or more computers in a network. Hub transfers the data from one computer to
another computer in a network. A hub simply forwards the packets to all the
other computers connected to it. Switch is also a device used to connect two or
more computers in a network. The basic difference between hub and switch is
that hub broadcasts the data to each and every device attached to it whereas
switch only sends the data to that specific device in the network.
4. Wired and Wireless transmission media –
Wired transmission media or medium
uses wires or cables to transmit data from one place to another place. In this
type of medium we use wires or cables. The data is transferred in the form of
electrical or light signal. There are various types of cables that can be used
for setting up a network. Some of them are twisted pair, coaxial cable and
optical fibre network. Wireless transmission media are type of media where data
is transferred from one place to another without using any wire or cable. Some
of the wireless transmission media are radio wave transmission, infrared
technology and microwave transmission.
5. Client – Server Network and Peer – to – Peer network –
Client Server Network is a network
where several computers called client are connected to the main computer called
the server. Server is a computer which provides services to the clients and
controls the access to hardware, software resources and other resources. While
Client is a computer which request services like data retrieval, storage, etc.
from the server is called the client. P2P is a network where few computers of
similar power and capacity are connected together. There are no exclusive
servers or clients in this network. Each computer can act as a server as well
as a client.
6. WAN and PAN –
A wide area network is a
telecommunication network that spread across cities, countries or continents. A
PAN is a computer network which is connected around a person. It is used to
communicate between devices like printers, phones, etc.
E. Answer the following –
1. Define a computer network.
A computer network is composed of
multiple computers connected together for the purpose of communication, sharing
data and resources, etc. The computers in a network may be linked through
cables, telephone lines, radio waves or infrared light beams.
2. Give two advantages of a computer network.
Communication: People use networks
to communicate with each other by exchanging messages and information.
Computers connected to each other allow information to get transferred easily
and quickly.
Cost effectiveness: Sharing of
resources results in reducing the additional cost of buying hardware and
software.
3. What is modem?
Modem is a device which helps the
computer to send the data over networks. Usually the data is transmitted from
one place to another place in the form of analog signal, but the computer
processes digital data so the modem helps to convert this digital data into
analog signal and send this data through telephone line or with the help of
some other media. The word modem is derived from the term modulator and
demodulator which mean to modulate the digital signal to analog signal and
demodulate the analog to digital signal.
4. Write short notes on Bluetooth Wireless Technology and
Wi-Fi?
Bluetooth is a wireless technology
that lets you talk and share information like music, videos, etc. Bluetooth
technology was invented in 1994 by engineers at Ericsson, a Swedish company. It
is built into electronic gadgets. Bluetooth technology sends information within
its personal space, which is called ‘PAN’. Wi-Fi stands for Wireless Fidelity.
It is used in wireless network technology that uses radio waves to provide
wireless high speed internet and network connections.
5. Explain bus and star topologies?
In Bus Topology a single cable
known as backbone or bus carries all the data (traffic). Communication travels
in both the directions along the line, and can be received by any node. All the
computers, printers and other peripheral devices that are being shared are
connected to the bus. This topology is
normally used for small network. A star topology is a network topology in which
all the network nodes are individually connected to a central switch/ hub which
acts as a central point of communication to pass on the messages.
6. What do you mean by network security? What are the two
levels of network security?
While working on a network, a
computer can be accessed by many users. It is important to protect the network
from unauthorised access and prevent the loss or misuse of data or information.
It is important to ensure that only authorized person access or modify data.
Protecting
data and resources from unauthorised access is known as network security.
There are two general levels of network security Login Security and Rights Security.
There are two general levels of network security Login Security and Rights Security.
How we write question no (d)
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Differentiate between and answer the following question both you have to do write n fair copy.
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