This page contains the CBSE Computer Science with Python class 12 Unit-5 chapter 2 Networking Concepts – II. You can find the solutions for chapter 2 of CBSE class 12 Computer Science with Python Exercise. So is the case if you are looking for CBSE class 12 Computer Science with Python related topic Networking Concepts – II questions and answers for the Exercise.
Exercise
Question 1
1. What do you mean by a transmission medium? Differentiate between guided and unguided transmission media.
Answer 1
Transmission medium is the communication channel that carries signal/data from one computer (sender) to another (receiver).
It can be either guided (wired) or unguided (wireless).
Difference:
Basis
Guided (Wired)
Unguided (Wireless)
Path
Data travels through a physical path.
Data travels through air/free space.
Examples
Twisted pair, coaxial, fibre optic.
Radio wave, microwave, satellite, infrared.
Question 2
2. Explain the structure of a coaxial cable and a fibre optic cable.
Answer 2
•
Coaxial cable: central copper conductor, insulating (dielectric) layer, metallic shield (braid/foil), and outer protective jacket. The shield helps reduce external interference.
•
Fibre optic cable: glass/plastic core, surrounding cladding, buffer/protective coating and outer jacket; data is carried as light pulses for high-speed transmission.
Question 3
3. What are advantages of fibre optic cable?
Answer 3
•
Very high bandwidth (supports very high-speed data transfer).
•
Low attenuation (low signal loss over longer distance).
•
Immune to electromagnetic interference, so noise is very low.
•
More secure and reliable communication than many copper-based media.
Question 4
4. Differentiate between a radio wave transmission and a microwave transmission.
Answer 4
Basis
Radio Wave
Microwave
Direction
Generally omnidirectional.
Highly directional.
Line of sight
Not strict in many cases.
Usually requires line-of-sight.
Frequency/Behavior
Lower frequency; can cover wider areas and may diffract around obstacles.
Higher frequency; narrow beam, better for focused high-capacity links.
Range/Use
Broadcast, mobile communication.
Point-to-point links, satellite/terrestrial high-speed links.
Question 5
5. Explain satellite communication. What are the advantages and disadvantages of using satellite communication?
Answer 5
In satellite communication, data is sent from earth station to satellite (uplink) and then retransmitted from satellite to destination earth station (downlink) for long-distance communication.
Advantages:
•
Very large geographical coverage.
•
Useful for remote/isolated regions where wired links are difficult.
•
Supports long-distance communication and broadcasting.
Disadvantages:
•
High setup and maintenance cost.
•
Propagation delay (latency).
•
Weather interference can affect quality.
•
Requires accurate alignment and specialized ground equipment.
Question 6
6. Define the term topology.
Answer 6
Topology is the pattern/arrangement of interconnection of nodes in a network (especially LAN).
It defines how devices are linked and how data flows between them.
Question 7
7. List any two advantages and any two disadvantages of Star topology.
Answer 7
Advantages
•
Failure of one link/node usually does not affect the whole network.
•
Fault detection and reconfiguration are easy because each node has an independent connection.
Disadvantages
•
Needs more cable, so installation cost is higher.
•
If the central hub/switch fails, the whole network goes down.
Question 8
8. How is Tree Topology different from Bus topology?
Answer 8
Basis
Bus Topology
Tree Topology
Structure
Single backbone cable.
Combination of bus and star (hierarchical branches).
Scalability
Limited scalability.
Better scalability for larger networks.
Traffic handling
More congestion as nodes increase on same backbone.
Traffic can be distributed across branches.
Fault impact
Backbone failure affects entire network.
Failure impact can be isolated to a branch segment.
Question 9
9. Identify the type of topology from the following.
a.
Each node is connected with the help of single cable.
b.
Each node is connected with the help of independent cable with central switching.
Answer 9
a.
Bus topology (all nodes share one common backbone/single cable).
b.
Star topology (each node has an independent cable to a central switch/hub).
Question 10
10. What do you mean by a modem? Why is it used?
Answer 10
Modem (MOdulator-DEModulator) is a device that converts digital signals to analog and analog to digital.
It is used to enable data communication over telephone/cable lines and connect a computer/network to Internet services.
Question 11
11. Explain the following devices:
a.
Switch
b.
Repeater
c.
Router
d.
Gateway
e.
Wi-Fi Card
Answer 11
a.
Switch: connects multiple computers in a LAN and forwards data intelligently to the intended port/device, reducing unnecessary traffic.
b.
Repeater: receives weak signal, amplifies/regenerates it, and retransmits it to extend network distance.
c.
Router: connects different networks and routes packets between them based on IP addressing.
d.
Gateway: connects dissimilar networks that may use different protocols/architectures and enables protocol translation.
e.
Wi-Fi Card: wireless network adapter used to connect a computer to Wi-Fi network without a physical cable.
Question 12
12. Show a network layout of star topology and bus topology to connect 4 computers.
Answer 12
Star topology (4 computers)
PC1
|
PC2 -[SWITCH]- PC3
|
PC4Bus topology (4 computers)
PC1 PC2 PC3 PC4
| | | |
===================== (BUS)Question 13
13. Ms. Anjali Singh, in charge of Knowledge centre in ABC school, recently discovered that the communication between her centre and the primary block of the school is extremely slow and signals drop quite frequently. The distance between these two blocks is 140 meters.
a.
Name the type of network.
b.
Name the device which may be used for smooth communication.
Answer 13
a.
LAN (Local Area Network) because both blocks are within the same school campus (local coverage).
b.
Repeater to boost/regenerate weak signals and improve communication quality over ~140 m distance.
Question 14
14. ABC International School is planning to connect all computers, each spread over distance of 50 meters. Suggest an economic cable type having high speed data transfer to connect these computers.
Answer 14
Ethernet twisted pair cable (UTP/CAT5e/CAT6) is an economical and high-speed choice for around 50 m connections.
It provides good data rate for school LAN use at lower cost than fibre in short-distance setups.
Question 15
15. Sahil wants to transfer data across two continents at very high speed. Write the name of the transmission medium that can be used to do the same. Write the type of network also.
Answer 15
Transmission medium:Optical fibre cable (international submarine fibre links).
Type of network:WAN.
Fibre is preferred for inter-continental links due to very high bandwidth and low signal loss over long distances.
Question 16
16. Mayank wants to transfer data within a city at very high speed. Write the name of the wired transmission medium that he should use. Write the type of network also.
Answer 16
Wired transmission medium:Optical fibre cable
Type of network:MAN.
For city-wide communication, MAN is appropriate, and optical fibre provides very high speed with reliable performance.
Question 17
17. Mr. Akash wants to send/receive email through internet. Which protocol will be used for this purpose?
Answer 17
SMTP (Simple Mail Transfer Protocol) is used for sending email, and POP3 (Post Office Protocol version 3) is commonly used for receiving email.
In simple flow: mail is sent from client to server using SMTP, and the receiver downloads mail from server using POP3.
Question 18
18. Answer the following questions in the context of a computer lab with 100 computers.
a.
Which device is used to connect all computers inside the lab?
b.
Which device is used to connect all computers to the internet using telephone wire?
Answer 18
a.
Switch (used to connect all computers within the lab LAN and forward data efficiently).
b.
Modem (used to connect the lab network to Internet service over telephone line).
Question 19
19. Name the device that establishes an intelligent connection between a local network and external network with completely different structures.
Answer 19
Gateway.
A gateway provides intelligent interconnection between a local network and an external dissimilar network, including protocol/format conversion when required.
Question 20
20. Name the network device that works like a bridge to establish connection between two networks but it can also handle networks with different protocols.
Answer 20
Router.
A router works like an intelligent bridge between networks and can route data packets even when connected networks use different protocols.