Chapter – 3 [Data Communications]- Short Questions & Answers

Q. What is data communication?

Ans.  Data communication is the exchange of data between two devices via some form of transmission media or Data communication transfer of data or information from one location to another is called data communication or the movement of encoded information by means of an electrical transmission system from one computer or device to other computer or device through communication channels.

Q. Define a communication channel.

Ans. It is a path by which data travels from sender to receiver. There are two types of communication channels. Guided Media (Cables-twisted pair, Coaxial, fiber optic) and Unguided Media (Microwave, satellite).

Q. What are the Components of Data Communication:

Ans. There are five components of data communication. The message, Sender, Receiver, Communication channel, Encoder, and Decoder

Q. What is a message?

Ans. The message is the information or data to be communicated. Messages can be text, numbers, pictures, sound, video, or any combination of these.

Q. What is a Sender?

Ans. The sender is the device that sends the data. It is also called a source or transmitter.

It can be a computer, telephone, camera, TV or so on.

Q. What is a Receiver?

Ans. The receiver is the device that receives the data. It is also called destination or sink. It can be a computer, telephone, TV, or so on.

Q. What are Encoder and Decoder?

Ans.  The encoder converts the digital signal to a form that can pass through the transmission medium.

Decoder converts signals from encoded form to a digital form understandable for the receiver.

Q. What is Signal?

Ans. The electromagnetic or light waves representing data are called signals. There are two forms of signals. Analog Signals, Digital Signals.

Q. What is an analog Signal?

Ans. These are continuous electrical signals in the form of waves. This wave is called a carrier wave. In analog signals, the transmitted power varies over a continuous range e.g. sound, light, and radio waves.

Q. What are the Characteristics of analog signals?

Ans.  There are two characteristics of analog signals

• Frequency: Number of times a wave repeats during a specific time. It 1s measured in hertz (Hz).
• Amplitude: It is the height of wave within a given period of time.