Radio Waves

Question 1

the physical interaction among electric charges, magnetic moments, and the electromagnetic field.

Answer 1

Electromagnetism

Question 2

Electromagnetic waves are generally known as ________ and obey the laws of _______.

Answer 2

light, optics

Question 3

a measurement of how often a recurring event such as a wave occurs in a measured amount of time

Answer 3

Frequency

Question 4

One completion of the repeating pattern is called a

Answer 4

cycle

Question 5

The distance from the “crest” (top) of one wave to the crest of the next wave is

Answer 5

the wavelength

Question 6

Energy in the form of wave

Answer 6

Electromagnetic radiation

Question 7

Light travels in _______ line, at a ________speed, in the form of _______

Answer 7

straight, constant, wave

Question 8

The existence of radio waves was proved by __________ in the year ______

Answer 8

Heinrich Hertz, 1880

Question 9

The basic building block of radio communication

Answer 9

radio wave

Question 10

Radio waves are a form of radiation known as electromagnetic waves. The wavelength of radio waves is longer than the infrared light.

Answer 10

Property 1

Question 11

Radio waves can travel for a long distance.

Answer 11

Property 2

Question 12

Radio waves can penetrate through materials.

Answer 12

Property 3

Question 13

Radio waves cannot be felt and they are invisible.

Answer 13

Property 4

Question 14

They travel at the speed of light in vacuum. When they travel through the materials the speed differs, depending on the object’s permeability and permittivity.

Answer 14

Property 5

Question 15

The wavelength range of radio waves is from thousands of metres to 30 mm. These correspond to a frequency from 3 Hertz to 109Hertz.

Answer 15

Property 6

Question 16

Radio waves are emitted naturally by lightning and astronomical objects that have a changing magnetic field. They are also created by varying electric currents.

Answer 16

Property 7

Question 17

Radio waves experience reflection, refraction, absorption, diffraction and polarisation.

Answer 17

Property 8

Question 18

Radio waves have both electric and magnetic components.

Answer 18

Property 9

Question 19

Formula for frequency

Answer 19

F = 1/T

Question 20

For the generation of radio waves, _____________ radiate EM energy

Answer 20

Accelerating charges

Question 21

For the generation of radio waves, If charges oscillate back and forth, It gets _________ too.

Answer 21

time-varying magnetic fields

Question 22

Amplitude Modulation (AM) that uses changes in the __________ to convey information

Answer 22

signal strength

Question 23

AM Radio uses frequency range from

Answer 23

530 kHz to 1700 kHz

Question 24

Frequency Modulation (FM) uses changes in the ____________ to convey information

Answer 24

wave’s frequency

Question 25

FM radio Spans __________ in 200 kHz intervals

Answer 25

87.8 MHz to 108.0 MHz

Question 26

Communication radios in general aviation aircraft use a portion of __________________, with frequencies between _______ to ______

Answer 26

the very high frequency (VHF) range, 118.0 MHz to 135.975 MHz

Question 27

the bent whip rods mounted on top of the cabin

Answer 27

VHF antennas

Question 28

Range of VHF transmissions is limited to

Answer 28

line of sight (obstructions such as buildings, terrains and the curvature of the earth block the radio waves)

Question 29

Radios are classified according to number of channels they can accommodate: ____-channel radio or ____-channel radio

Answer 29

320 or 720

Question 30

Since the communication radios usually combine a transmitter and a receiver, they are called ________

Answer 30

transceivers