Department of Electronics Engineering – UoP
Wireless Communication Systems
EM Waves Propagation – Quiz No. 1
Engr. Cezar N. Velasco Jr.
Name: ___________________________________________
Course/Year: ______________________________________
Enclose your answer with a red mark square. (x4 = 100 points)
1
An antenna can be thought of as a(n)
a. Oscillator
b. Capacitor
c. Transducer
d. Frequency multiplexer
2
A wave that is characterized by having its direction of propagation perpendicular to its oscillation is known as
a. Isotropic
b. Transverse
c. Polarized
d. Refractive
3
Which is not an effect of our environment on wave propagation?
a. Radiation
b. Reflection
c. Refraction
d. Diffraction
4
A point in space that radiates electromagnetic energy equally in all directions is called
a. Transverse
b. Isotropic point source
c. Omnisphere
d. Shadow zone
5
The process of waves, which traveling in straight paths, bending around an obstacle is
a. Radiation
b. Reflection
c. Refraction
d. Diffraction
6
Which is not one of the basic modes of getting a radio wave from the transmitting to receiving antenna?
a. Ground wave
b. Shadow wave
c. Space wave
d. Satellite link
e. Sky wave
The type of wave that is most affected by the D, E, and F layers of the ionosphere is:
a. Ground wave
b. Space wave
c. Sky wave
d. Satellite
7
8
The largest frequency that will be returned to earth when transmitted vertically under given ionospheric
conditions is called the
Department of Electronics Engineering – UoP
Wireless Communication Systems
EM Waves Propagation – Quiz No. 1
Engr. Cezar N. Velasco Jr.
a. Critical frequency
b. Maximum usable frequency (MUF)
c. Optimum working frequency (OWF)
d. Skip zone
9
The characteristic impedance of free space is
a. Not known
b. Infinite
c. 50
d. 377
10
The area between the point where the ground wave ends and first sky wave returns is called the
a. Quiet zone
b. Skip zone
c. Null Zone
d. All the above
e. a and b
11
The refraction and reflection action of a skywave between the ionosphere and ground is known as
a. Space diversity
b. Skip
c. Tropospheric scattering
d. Fading
12
A satellite communication system used by companies such as K-Mart to quickly verify credit cards and check
inventory data is called
a. VSAT
b. MSAT
c. SATCOM
d. WESTAR
13
A common type of radio wave interference is
a. EMI
b. Fading
c. Reflections
d. All the above
14
Diversity reception does not include:
a. Space diversity
b. Time diversity
c. Frequency diversity
d. Angle diversity
15
When installing a receiving antenna, you can often overcome diffraction problems by finding a
a. Null zone
b. Downlink
c. Hot spot
d. Skip zone
Department of Electronics Engineering – UoP
Wireless Communication Systems
EM Waves Propagation – Quiz No. 1
Engr. Cezar N. Velasco Jr.
16
Radio waves were first predicted mathematically by:
a. Armstrong
b. Hertz
c. Maxwell
d. Marconi
17.
Radio waves were first demonstrated experimentally by:
a. Armstrong
b. Hertz
c. Maxwell
d. Marconi
18.
The "attenuation of free space" is due to:
a. losses in the characteristic impedance of free space
b. losses due to absorption in the upper atmosphere
c. the decrease in energy per square meter due to expansion of the wavefront
d. the decrease in energy per square meter due to absorption of the wavefront
19.
Radio waves would most strongly reflect off:
a. a flat insulating surface of the right size
b. a flat dielectric surface of the right size
c. a flat metallic surface of the right size
d. a flat body of water
20.
Which polarization can be reasonably well received by a circularly polarized antenna?
a. vertical
b. horizontal
c. circular
d. all of the above
21.
Space waves are:
a. line of sight
b. reflected off the ionosphere
c. same as sky waves
d. radio waves used for satellite communications
22.
A 20-dB reduction in the strength of a radio wave due to reflection is called:
a. fading
b. diffraction
c. frequency diversity
d. spatial diversity
23.
"Ghosts" on a TV screen are an example of:
a. fading
b. diffraction
c. multipath distortion
d. cancellation due to reflection
24.
Troposphere is the:
a. highest layer of the atmosphere
b. middle layer of the atmosphere
c. lowest layer of the atmosphere
d. the most ionized layer of the atmosphere
25.
Meteor-trail propagation is:
a. used for radio telephony
d. not possible
b. used to send data b radio
c. also called ducting