3001comms

Question 1

antenna is not grounded at one end?

Answer 1

Dipole

Question 2

…………… polarization is employed in FM broadcasting

Answer 2

Horizontal

Question 3

…………… polarization is employed in AM broadcasting.

Answer 3

Vertical

Question 4

An energy which radiates in the form of radio waves; infrared waves; light waves; x-rays; etc.

Answer 4

Electromagnetic

Question 5

…………. is an antenna made up of a number of full wavelengths.

Answer 5

Long wire

Question 6

When antennas are closed to the ground; ………….. polarization is ideal.

Answer 6

vertically polarized

Question 7

makes an antenna physically long but electrically short.

Answer 7

Adding C in series

Question 8

antennas is best excited from a waveguide

Answer 8

Horn

Question 9

very useful as a multiband HF receiving antenna.

Answer 9

Log-periodic

Question 10

An ungrounded antenna near the ground acts s

Answer 10

antenna array

Question 11

Good grounding is important for

Answer 11

vertical antennas

Question 12

ratio of the maximum radiation intensity to the average radiation intensity?

Answer 12

Directivity gain

Question 13

………….. is the angle between the half-power radiation points.

Answer 13

Beamwidth

Question 14

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Answer 14

increased

Question 15

What is the polarization of a discone antenna?

Answer 15

Vertical

Question 16

When speaking of antennas; ……….. is a section which would be a complete antenna by itself

Answer 16

bay

Question 17

range of frequencies are most omnidirectional horizontally polarized antennas used?

Answer 17

VHF; UHF

Question 18

If the current ratios of the two or more elements must be held 5% and the phase angle to 3 degrees; the antenna is called a

Answer 18

critical phased array

Question 19

non-resonant antenna

Answer 19

Rhombic antenna

Question 20

Very low signal strength in antenna.

Answer 20

Null

Question 21

………… is the measurement of a unilateral antenna properties of directivity

Answer 21

Beamwidth

Question 22

In testing transmitter to prevent interfering with other stations; which type of antenna must be used?

Answer 22

Dummy antenna

Question 23

The best solution of fading is ………….

Answer 23

space diversity

Question 24

…………. is the amount of uncertainty in a system of symbols.

Answer 24

Entropy

Question 25

Top loading is used in an antenna in order to increase its ................

Answer 25

effective height

Question 26

A horizontal antenna is ...............

Answer 26

horizontally polarized

Question 27

All elements in a beam ............ antennas are in line.

Answer 27

collinear

Question 28

................. is the antenna with a number of half-wave antenna on it.

Answer 28

Antenna array

Question 29

antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization?

Answer 29

Marconi antenna

Question 30

An antenna with very high gain and very narrow beamwidth.

Answer 30

Parabolic dish antenna

Question 31

.............. is the horizontal pointing angle of an antenna.

Answer 31

Azimuth

Question 32

Discone radiation pattern is ..............

Answer 32

omnidirectional

Question 33

.............. is an open-ended slot antenna.

Answer 33

Notch antenna

Question 34

radiation characteristic of a dipole antenna

Answer 34

Bidirectional

Question 35

antenna with unity gain

Answer 35

Isotropic

Question 36

An antenna which is one-tenth wavelength long.

Answer 36

Elementary doublet

Question 37

The antenna radiates .......... polarized waves when the transmitter antenna is horizontally installed.

Answer 37

horizontally

Question 38

Comparing the signal strength arriving at the driven element from the desired direction to the signal strength reaching the driver from the opposite direction.

Answer 38

Front-to-back ratio

Question 39

................ of an antenna is a measure of how the antenna concentrates its radiated power in a given direction.

Answer 39

Gain

Question 40

Shortening effect of an antenna that makes it appear as if it were 5% longer

Answer 40

End effect

Question 41

Actual height of antenna should be at least

Answer 41

quarter wavelength

Question 42

............... is an antenna array which is highly directional at right angles to the plane of the array?

Answer 42

Broadside array

Question 43

The directivity pattern of an isotropic radiator is

Answer 43

sphere

Question 44

A theoretical reference antenna that provides a comparison for antenna measurements.

Answer 44

isotropic radiator

Question 45

Increasing the electrical length of an antenna means

Answer 45

add an inductor in series