Ex. Module 10 Ch. 2&4.txt

The induction field is made up of which of
the following fields?

After the radiation field leaves an antenna,
what is the relationship between the E and
H fields with respect to (a) phase and
(b) physical displacement in space?

What is the first harmonic of a radio wave
that has a fundamental frequency of 2,000
kHz?

A radio wave with a frequency of 32 kHz
is part of which of the following frequency
bands?

A frequency of 3.5 GHz falls into what rf
band?

A radio wavelength expressed as 250
meters may also be expressed as how
many feet?

An increase in the frequency of a radio
wave will have what effect, if any, on the
velocity of the radio wave?

An increase in frequency of a radio wave
will have what effect, if any, on the
wavelength of the radio wave?

Energy radiated from an antenna is
considered horizontally polarized under
which of the following conditions?

The ability of a reflecting surface to reflect
a specific radio wave depends on which of
the following factors?

The bending of a radio wave because of a
change in its velocity through a medium isknown as

Radio communications can be diffracted
to exceptionally long distances through the
use of (a) what frequency band at (b) whatrelative power level?

Electrically charged particles that affect
the propagation of radio waves are found
in what atmospheric layer?

Most weather phenomena take place in
which of the following region of the
atmosphere?

Radio wave propagation has the least
effect because of its constancy on which
of the following atmospheric layers?

Long range, surface-wave
communications are best achieved when
the signal is transmitted over seawater
with (a) what polarization at (b) what
relative frequency?

The Navy’s long-range vlf broadcasts are
possible because of the advantages of
which of the following types of
propagation?

A space wave (a) is primarily a result of
refraction in what atmospheric layer and
(b) extends approximately what distance
beyond the horizon?

The signal of a space wave is sometimes
significantly reduced at the receiving site
because of which of the following
interactions?

For long-range communications in the hf
band, which of the following types of
waves is most satisfactory?

Ionization in the atmosphere is produced
chiefly by which of the following types of
radiation?

Ultraviolet waves of higher frequencies
produce ionized layers at what relative
altitude(s)?

The density of ionized layers is normally
greatest during which of the following
periods?

Compared to the other ionospheric layers
at higher altitudes, the ionization density
of the D layer is

What two layers in the ionosphere
recombine and largely disappear at night?

For hf-radio communications covering
long distances, what is the most important
layer of the ionosphere?

Refraction of a sky wave in the ionosphere
is influenced by which of the following
factors?

The distance between the transmitter and
the nearest point at which refracted waves
return to earth is referred to as the

When ground-wave coverage is LESS
than the distance between the transmitter
and the nearest point at which the
refracted waves return to earth, which of
the following reception possibilities
should you expect?

The greatest amount of absorption takes
place in the ionosphere under which of the
following conditions?

If the signal strength of an incoming signal
is reduced for a prolonged period, what
type of fading is most likely involved?

Radio waves that arrive at a receiving site
along different paths can cause signal
fading if these waves have different

The technique of reducing multipath
fading by using several receiving antennas
at different locations is known as what
type of diversity?

Receiving sites located near industrial
areas can expect to have exceptionally
large losses in signal quality as a result of
which of the following propagation
situations?

Which of the following ionospheric
variation causes densities to vary with the
axial rotation of the sun?

Which of the following ionospheric
variation causes densities to vary with the
position of the earth in its orbit around the
sun?

Which of the following ionospheric
variation causes densities to vary with the
time of the day?

What factor significantly affects the
frequency of occurrence of the sporadic-E
layer?

A sudden and intense burst of ultraviolet
light is especially disruptive to
communications in which of the following
frequency bands?

Hf

For a radio wave entering the atmosphere
of the earth at a given angle, the highest
frequency at which refraction will occur is
known by which of the following terms?

The most consistent communications can
be expected at which of the following
frequencies?

In determining the success of radio
transmission, which of the following
factors is the LEAST predictable?

At frequencies above 100 MHz, the
greatest attenuation of rf energy from
raindrops is caused by which of the
following factors?

Under certain conditions, such as ducting,
line-of-sight radio waves often propagate
for distances far beyond their normal
ranges because of which of the following
factors?

When ducting is present in the
atmosphere, multihop refraction of
line-of-sight transmission can occur
because of which of the following factors?

A propagation technique used to extend
uhf transmission range beyond the horizon
uses which of the following propagation
characteristics?

What effect, if any, does the radiation
angle of a transmitting antenna have on
the reception of communications by
tropospheric scatter?

Radio energy is transmitted through
which of the following mediums?

Energy is transmitted from a transmitter
into space using which of the following
devices?

Transmitted rf energy takes what form as
it is sent into space?

The dimensions of a transmitting antenna
are determined by which of the following
factors?

A device used to radiate or receive
electromagnetic wave energy is referred
to as a/an

An antenna that can be mounted to
radiate rf energy either vertically or
horizontally is classified as which of the
following types?

A complete antenna system consists of
which of the following components?

What component in an antenna system
transfers energy from the transmitter to
the antenna?

The type, size, and shape of an antenna
are determined by which of the following
factors?

Moving electric and magnetic fields in
space have what (a) phase and
(b) angular relationships?

What is the length of each half of the
wire for a dipole antenna?

On a standing wave, the points of high
current and voltage are identified by
which of the following terms?

The presence of standing waves indicates
which of the following conditions of an
antenna?

The antenna property that allows the
same antenna to both transmit and
receive energy is

There is a ratio between the amount of
energy propagated in certain directions
by a directional antenna compared to the
energy that would be propagated in these
directions if the antenna were not
directional. This ratio is known as which
of the following antenna characteristics?

The polarization plane of the radiation
field is determined by which of the
following fields?

For best reception of a signal from a
horizontally polarized antenna, the
receiving antenna should be mounted so
that it has what relationship with the
transmitting antenna?

An electric field that rotates as it travels
through space exhibits what type of
polarization?

For ground-wave transmissions, what
type of polarization is required?

For high-frequency operation, which of
the following antenna polarization
patterns is preferred?

Omnidirectional transmission is obtained
from which of the following antennas?

An isotropic radiator radiates energy in
which of the following patterns?

An ordinary flashlight is an example of
what type of radiator?

The area enclosed by the radiation
pattern is the

Inserting an inductor or capacitor in
series with an antenna is one method of
electrically changing the electrical length
of an antenna. What is this method
called?

Many complex antennas are constructed
from what basic antenna?

On an energized half-wave antenna,
which of the following electrical
conditions exist?

A method of feeding energy to a halfwave
antenna is to connect one end
through a capacitor to the output stage.
What is this method of feeding called?

An antenna supplied by the center-feed
method is fed at what point?

The basic Marconi antenna has which of
the following characteristics?

A series of conductors arranged in a
radial pattern and buried in the ground
beneath the antenna is referred to as a

A folded dipole can be used instead of a
simple, center-fed dipole for which of the
following purposes?

An antenna arrangement that has
elements aligned in a straight line is
referred to as what type array?

To select a desired signal and
discriminate against interfering signals,
the receiving antenna should have which
of the following characteristics?

What is the maximum number of
elements ordinarily used in a collinear
array?

Compared with collinear arrays,
broadside arrays have which of the
following advantages?

What is the range of electrical spacing
between the elements of an end-fire
array?

Assuming that the elements are correctly
spaced, the directivity of an end-fire
array may be increased by which of the
following actions?

The ratio of energy radiated by an array
in the principal direction of radiation to
the energy radiated in the opposite
direction describes which of the
following relationships?

The Yagi antenna is an example of what
type of antenna array?

An antenna which is designed especially
for vertically-polarized ground waves at
low frequencies is the

A rhombic antenna is essentially a
combination of which of the following
antennas?

A rhombic antenna has which of the
following advantages?

The principal disadvantage of the
rhombic antenna is its

The unidirectional radiation pattern of
the rhombic antenna is caused by which
of the following antenna characteristics?

Horizontal half-wave antennas mounted
at right angles to each other in the same
horizontal plane make up which of the
following antennas?

The most common means of obtaining a
low-radiation angle from a vertical
quarter-wave antenna is by what
procedure?

A corner reflector antenna is used for
which of the following purposes?

If a corner-reflector antenna is
horizontally polarized, its radiation
pattern will take on what shape?

When radio or radar antennas are
energized by transmitters, you must not
go aloft until which of the following
requirements are met?