Friday, February 14, 2025

Class IX Lesson 9 ( Data Communication Q/A) English Medium

 

LONG ANSWER TYPE QUESTIONS

1. What is basic communication model? Explain its each block with a suitable figure.

Ans:-
The basic communication model represents how information is transmitted from a sender to a receiver through a medium. It consists of the following blocks:

  1. Sender (Transmitter): The originator of the message, such as a computer, mobile phone, or human voice.
  2. Encoder: Converts the message into signals suitable for transmission.
  3. Channel: The medium through which the signal travels, such as wired or wireless networks.
  4. Decoder: Converts received signals back into understandable information.
  5. Receiver: The final destination that interprets the message.
  6. Noise: Any unwanted disturbance that affects the message clarity.
  7. Feedback: The response from the receiver to confirm message reception.

A simple diagram of the communication model:


Sender → Encoder → Channel (Noise) → Decoder → Receiver → Feedback

This model ensures effective data transmission in communication systems.


2. Draw a simple block diagram of a communication system and explain the working of each block.

Ans:-
A basic communication system consists of:

  1. Information Source: Produces the message to be transmitted.
  2. Transmitter: Converts the message into a transmittable signal.
  3. Channel: The medium (air, cable, fiber optics) that carries the signal.
  4. Receiver: Receives and processes the signal.
  5. Destination: The final recipient of the message.

Block Diagram:

Information SourceTransmitterChannelReceiverDestination

Each block works together to ensure smooth communication between sender and receiver.


3. Explain the following:

(a) Analog Communication
Ans:- Analog communication transmits information using continuous signals. Examples include radio and telephone communication. It is susceptible to noise and interference.

(b) Digital Communication
Ans:- Digital communication transmits information using discrete signals (0s and 1s). It is more reliable, efficient, and widely used in computers and mobile networks.


4. Explain communication protocol and its function.

Ans:-
A communication protocol is a set of rules that governs data exchange between devices in a network.

Functions of Communication Protocols:

  • Data formatting and transmission.
  • Error detection and correction.
  • Ensuring security and authentication.
  • Managing network traffic and routing.

Examples: TCP/IP, HTTP, FTP.


5. What do you understand by parallel as well as sequential transmission? Explain in detail.

Ans:-
Parallel Transmission: Multiple bits are sent simultaneously over separate channels. It is faster but requires more resources. Example: Computer buses.

Sequential Transmission: Data is sent bit by bit in a sequential manner over a single channel. It is slower but cost-effective. Example: USB communication.


6. What is multiplexing? What are its types? Explain briefly.

Ans:-
Multiplexing is a technique that allows multiple signals to be transmitted over a single communication channel.

Types of Multiplexing:

  1. Frequency Division Multiplexing (FDM): Uses different frequency bands.
  2. Time Division Multiplexing (TDM): Allocates time slots to different signals.
  3. Space Division Multiplexing (SDM): Uses separate physical pathways.

SHORT ANSWER TYPE QUESTIONS

1. What do you understand by computer and communication? What are its uses?
Ans:- Computers and communication systems work together to enable data exchange. They are used in emails, online banking, video conferencing, and cloud computing.


2. What is a signal, and what are its types?
Ans:- A signal is a waveform that carries data. It can be analog (continuous) or digital (discrete).


3. What are the main types of modulation?
Ans:-

  • Amplitude Modulation (AM)
  • Frequency Modulation (FM)
  • Phase Modulation (PM)

4. What are synchronous and asynchronous transmission?
Ans:-

  • Synchronous Transmission: Data is sent in continuous blocks with timing synchronization.
  • Asynchronous Transmission: Data is sent in independent units with start/stop bits.

5. What are data transmission lines and their types?
Ans:- Data transmission lines are communication paths for data transfer. Types:

  • Wired (Fiber optic, Coaxial, Twisted pair)
  • Wireless (Radio waves, Microwaves, Satellites)

VERY SHORT ANSWER TYPE QUESTIONS

1. What is data?
Ans:- Data is raw information processed to produce meaningful output.

2. What do you understand by information?
Ans:- Processed and meaningful data is called information.

3. What is a signal?
Ans:- A signal is an electrical waveform that carries data.

4. What are analog and digital transmission?
Ans:- Analog transmission is continuous, while digital transmission is in binary (0s & 1s).

5. How is data transferred in data transmission?
Ans:- Through wired or wireless communication channels.

6. How will you measure data transfer speed?
Ans:- In bits per second (bps).

7. What is modulation and demodulation?
Ans:-

  • Modulation: Converting digital signals to analog.
  • Demodulation: Converting analog signals to digital.

MULTIPLE CHOICE QUESTIONS

  1. Important part of a communication system:
    Ans:- (d) All of these

  2. How will you measure speed of data transfer?
    Ans:- (b) BPS

  3. What does the source give to the receiver?
    Ans:- (b) Information

  4. Which mode of communication?
    Ans:- (d) All of these

  5. Which has weak speed of data transfer?
    Ans:- (a) Narrow band

  6. Speed in wide band transmission is:
    Ans:- (c) Above 500000 BPS

  7. Conversion of digital to analog signals is called:
    Ans:- (a) Modulation

  8. What do we use to connect a telephone to a computer for data transfer?
    Ans:- (c) Modem

  9. File transfer is which kind of function?
    Ans:- (a) Network

  10. In which of the following are bits transferred one by one?
    Ans:- (c) Sequential transmission

  11. Which of the following is not a type of media?
    Ans:- (d) MODEM

  12. Data is transmitted in the form of light waves in:
    Ans:- (b) Fiber optics

  13. Which of the following has the fastest data transmission speed?
    Ans:- (b) Fiber optics

  14. An example of a simplex device is:
    Ans:- (c) Walkie-talkie

  15. In optical fiber communications, the signal source is:
    Ans:- (a) Light

No comments:

Post a Comment

Class IX Lesson 11 (Internet) Hindi Medium

  दीर्घ उत्तरीय प्रश्न  1. इंटरनेट क्या है? इसके मुख्य उपयोग क्या हैं? उत्तर: इंटरनेट एक वैश्विक नेटवर्क है जो लाखों कंप्यूटरों को आपस में ज...