Question

Which of the following lists the steps of technological development in the

Answer 1

Answer:

C. (1) Telegraph; (2) telephone; (3) cordless telephone; (4) mobile

phone

Explanation:

Telegraphs were used as a source of communication in very early days. Telegraph is a device which uses electrical signals to transmit messages across long distances and it was invented in 1830.

Telephone is another communication device which was first used in 1876. It is an electronic device which is stationary and fixed at a position through wiring and it is used for communications across short or long distances.

After telephone, cordless telephone came into existence as an advanced form of telephone because cordless is not fixed at a location through wiring and it could be moved from one place to another within a short range. It was first introduced in 1995.

Mobile phone is the most advanced type of telephone used for communication and they are not fixed at a position. People can carry mobiles with them even if they are travelling across long distances. They first came in use in recent years.

Answer 2

The answer is D. Telegraph, telephone, cordless phone , mobile