Chapter 1

Question 1

Sound travels through air as __________ or rapid fluctuations in air pressure.

Answer 1

pressure waves

Question 2

Rapid fluctuations in air pressure.

Answer 2

pressure waves

Question 3

The rates of fluctuation in air pressure that we humans can perceive as sound is commonly said to vary between ____

Answer 3

20 cycles per second and 20,000 cycles per second.

Question 4

Few adult individuals can hear above

Answer 4

15 to 17 kHz

Question 5

When sound waves hit a microphone, the pressure fluctuations are converted into fluctuations of ___________ on a wire.

Answer 5

electric voltage

Question 6

The fluctuations of voltage that represent sound and travel down a wire are known as an ____________

Answer 6

audio signal

Question 7

__________ are translated back into sounds by speakers and headphones.

Answer 7

Signals

Question 8

Radio propagates sound signals long distances through air and space by the use of high frequency ________

Answer 8

carrier waves

Question 9

The sound signal is imposed on the carrier wave by a process called ___________

Answer 9

modulation

Question 10

The carrier wave then carries the signal the long distance to the _________

Answer 10

radio receiver

Question 11

FM stands for ____________

Answer 11

Frequency Modulation

Question 12

In FM radio, the audio signals are imposed upon the carrier waves using ____________

Answer 12

frequency modulation

Question 13

This means that the instantaneous frequency of the high frequency carrier wave (91,500,000 Hertz - cycles per second) is altered (modulated) by the instantaneous value of the audio signal.

Answer 13

frequency modulation

Question 14

In AM radio, it is the ________ of the carrier signal that is modulated.

Answer 14

amplitude

Question 15

In 1864 ____________ showed mathematically (theoretically) that electromagnetic waves could propagate through free space.

Answer 15

James Clerk Maxwell

Question 16

The discovery of these _____________ (radio waves) prompted many experiments by physicists.

Answer 16

“Hertzian waves”

Question 17

In 1886 ____________ noticed the same sparking phenomenon and was able to demonstrate the existence of electromagnetic waves in an experiment confirming Maxwell’s theory of electromagnetism.

Answer 17

Heinrich Rudolf Hertz

Question 18

The father of radio

Answer 18

Guglielmo Marconi

Question 19

In _____, Guglielmo Marconi began pursuing the idea of building a wireless telegraphy system based on Hertzian waves (radio).

Answer 19

1894

Question 20

_______ gained a patent on the system in 1896 and developed it into a commercial communication system over the next several years.

Answer 20

Marconi

Question 21

Early uses were maritime, for sending telegraphic messages using ___________ between ships and land.

Answer 21

Morse code

Question 22

Radio was _____ to develop.

Answer 22

slow

Question 23

One of the most memorable uses of early radio was during the sinking of the __________, including communications between operators on the sinking ship and nearby vessels, and communications to shore stations listing the survivors.

Answer 23

Titanic in 1912

Question 24

___________ accelerated the development of radio for military communications

Answer 24

World War I

Question 25

_________ was a huge proponent of radio. Communication between ships allowed precise locations to be determined.

Answer 25

The US Military

Question 26

_____________ held patents and manufactured virtually all parts required for radio broadcast.

Answer 26

British Marconi company

Question 27

In _____, General Electric developed a new radio technology. Was poised to sell to Marconi comp. GE president and secretary of Navy came to an “agreement.

Answer 27

1919

Question 28

________ was formed as a subsidiary of GE

Answer 28

RCA

Question 29

RCA

Answer 29

formed as a subsidiary of GE

Question 30

________ brought together the major companies involved in radio research. Pooled patents & coordinated research

Answer 30

RCA