Q.1: At what speed do wireless waves move? What other waves move at this speed?
Ans: The wireless waves move at the speed of 299792.5 Kilometres per second. The light waves also move at the same speed.
Q.2: Why were wireless waves once called Hertzian waves?
Ans: Wireless waves were once called Hertzian waves because Heinrich Hertz, the German scientist was the first person who discovered these waves.
Q.3: In what years were wireless signals first transmitted over the
Ans: The wireless signals were first transmitted over the
Q.4: What facts are given in the text about the first use of wireless to bring help to a ship in distress?
Ans: When the
Q.5: Could speech be transmitted in the early days of wireless signalling? If not how were messages transmitted?
Ans: No, speech could not be transmitted in the early days of wireless signalling. The Morse code was sued instead of speech.
Q.6: During what period did sound broadcasting became generally established?
Ans: Sound broad casting became generally established in 1920’s.
Q.7: In what way is television an advance upon sound broad-casting?
Ans: Television is an advance upon sound broadcasting since pictures and not just sound can be sent by it.
Q.8: Is television in colour possible? If so, why is it not in general use?
Ans: Television in colour has been made possible. It is not in general use because it is expensive.
Q.9: What is the function of Radar?
Ans: The function of Radar is to locate position of aircraft ship.
Q.10: What use can the astronomer make of radio?
Ans: The astronomer can now explore the vast universe by the use of radio telescope. It works by detecting radio waves sent by distant stars.
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