NAVEDTRA 14182A Ch2

Question 1

Which 2 basic fields are associated with every antenna

Answer 1

Induction

Radiation

Question 2

In an antenna, which field is associated with energy stored

Answer 2

Induction

Question 3

Which type of antenna has an electrical length equal to HALF the WAVE of the signal being transmitted?

Answer 3

Half wave antenna

Question 4

What is an energy wave called that is generated by a transmitter

Answer 4

Radio wave

Question 5

What is the basic shape of the wave generated by a transmitter
(Radio wave)

Answer 5

Sine wave

Question 6

What is the NUMBER OF CYCLES of a sine wave that are completed in 1 second known as

Answer 6

Frequency

Question 7

Between 3KHz and _____ are commonly used for radio communications

Answer 7

300GHz

Question 8

Useable radio frequencies range roughly through 10KHz to _____.

Answer 8

100GHz

Question 9

Frequency ranges:
VLF-
LF-
MF-
HF-
VHF-
UHF-
SHF-
EHF-

Answer 9

Very Loud Music Has Very Unusual Side Effect

VLF- 3 - 30 KHZ
LF- 30- 300KHz
MF- 300KHz - 3 MHz
HF- 3MHz - 30MHz
VHF-30 - 300MHz
UHF- 300MHz - 3GHz
SHF- 3 - 30GHz
EHF- 30-300GHz

Question 10

What is the property of a radio wave which is simply the amount of TIME required for the completion of one full cycle

Answer 10

Period

Question 11

What is the SPACE called occupied by 1 full cycle of a radio wave at any given instant

Answer 11

Wavelength

Question 12

What is the speed of light

Answer 12

186,000 miles per second

Question 13

Where must the receiving antenna be located for maximum absorption of energy from the electromagnetic fields

Answer 13

Plane of polarization

Question 14

The TROPOSPHERE extends from the surface of the earth to a height of ________ miles at the equator

Answer 14

11.3 miles

Question 15

The TROPOSPHERE extends from the surface of the earth to a height of ________ miles at the north and South Pole

Answer 15

3.7 miles

Question 16

Which atmosphere layer has relatively NO EFFECT on radio waves because it is a calm region with little to no temp change

Answer 16

Stratosphere

Question 17

The ionosphere extends upward from about 31.1 miles to a height of about how many miles above the earths surface

Answer 17

250 miles

Question 18

Which frequency band is used for sky wave propagation

Answer 18

HF

Question 19

What is the process know as upsetting electrical neutrality

Answer 19

Ionization

Question 20

What occurs when free electrons and positive ions COLLIDE with each other

Answer 20

Recombination

Question 21

How many layers is the ionosphere composed of

Answer 21

3

1) D
2) E
3) F.
a) f1
b) f2

Question 22

What is the DISTANCE from the transmitter to the point where the sky wave first returns to the earth

Answer 22

Skip distance

Question 23

What results in the loss of energy of a radio wave and has a pronounced effect on both the strength of the signal received and the ability to communicate over a long distance

Answer 23

Absorption

Question 24

Fading on ionospheric circuits is mainly a result of what?

Answer 24

Multi path propagation

Question 25

There is little natural interference above what frequency

Answer 25

Above HF

Above 30MHz

Question 26

What are responsible for variations in the ionization level of the ionosphere

Answer 26

Sunspots

Question 27

Long distance propagation of HF radio waves is almost totally “blanked out” when what occurs

Answer 27

“SID”

Sudden ionospheric disturbance

Question 28

Rain drops cause greater attenuation by scattering then by absorption at frequencies above what

Answer 28

100 MHz

Question 29

Fog can cause serious attenuation by absorption at frequencies above what

Answer 29

2GHZ

Question 30

What is the condition when layers of warm air are formed above layers of cool air is known as

Answer 30

Temperature inversion

Question 31

What region does virtually all weather phenomena occur in

Answer 31

Troposphere