Mohan went to the market to purchase a TV set. He got confused with so many features and functions of electronic appliances. He took the help of his friend Sohan, a science student.Sohan explained him about the communication system, digital and analog signals. This knowledge proved of great help to Mohan in purchasing a colour TV.
Read the above passage and the answer the following questions:
(i)  What do you mean by the term communication?
(ii) Which type of signals are better?
(iii) What type of nature Sohan has?
(iv)What is the minimum number of communication satellites required for global communication coverage?

In the famous conversation, Rakesh Sharma, the first Indian Astronaut in space, was asked by the Prime Minister Indira Gandhi as to how India looked from space.To which he replied,'Sare Jahan Se Achcha' (better than the whole world).
Read the above passage and answer the following questions:
(i)   Which scientific mode of communication enabled the Prime Minister to speak to the Astronaut?
(ii)   Name the scientific values displayed in this anecdote.
(iii) Which values are being reflected in the reply given by the astronaut?
(iv) Give one more example of this scientific mode of communication in everyday life situations.

Raj was cycling from his village to a neighbouring village.On the way, he met an old man who was walking in the direction of the same neighbouring village. Raj invited the old man to sit on his cycle and took him to the neighbouring village.The old man got down from the cycle, thanked Raj and gave him blessing.
Read the above passage and answer the following questions:
(i)  What are the values displayed by Raj?
(ii) Can you relate the given paragraph with the process of modulation?

Group discussion was arranged in class XII on the topic of atmosphere. Three groups were made. Teacher asked the question "why can Moonbe not used as a communication satellite?" Answers were given by all the three groups. Each, group can give only one reason. Teacher told them that reason given by each group is correct. The groups collected all the three, reasons and came to correct conclusion,"
(i) Give the correct reason for the above question.
(ii) What values were showed by all the three groups?