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WorksheetsHam Radio General Questions Till 2019 Set G9C
Total questions: 20
Worksheet time: 20mins
Name
Class
Date
1.
G9C01 Which of the following would increase the bandwidth of a Yagi antenna?
a)
A. Larger diameter elements
b)
B. Closer element spacing
c)
C. Loading coils in series with the element
d)
D. Tapered-diameter elements
2.
G9C02 What is the approximate length of the driven element of a Yagi antenna?
a)
A. 1/4 wavelength
b)
B. 1/2 wavelength
c)
C. 3/4 wavelength
d)
D. 1 wavelength
3.
G9C03 Which statement about a three-element, single-band Yagi antenna is true?
a)
A. The reflector is normally the shortest element
b)
B. The director is normally the shortest element
c)
C. The driven element is the longest element
d)
D. Low feed point impedance increases bandwidth
4.
G9C04 Which statement about a three-element, single-band Yagi antenna is true?
a)
A. The reflector is normally the longest element
b)
B. The director is normally the longest element
c)
C. The reflector is normally the shortest element
d)
D. All of the elements must be the same length
5.
G9C05 How does increasing boom length and adding directors affect a Yagi antenna?
a)
A. Gain increases
b)
B. Beamwidth increases
c)
C. Front to back ratio decreases
d)
D. Front to side ratio decreases
6.
G9C06 What configuration of the loops of a two-element quad antenna must be used for the antenna to operate as a beam antenna, assuming one of the elements is used as a reflector?
a)
A. The driven element must be fed with a balun transformer
b)
B. There must be an open circuit in the driven element at the point opposite the feed point
c)
C. The reflector element must be approximately 5 percent shorter than the driven element
d)
D. The reflector element must be approximately 5 percent longer than the driven element
7.
G9C07 What does "front-to-back ratio" mean in reference to a Yagi antenna?
a)
A. The number of directors versus the number of reflectors
b)
B. The relative position of the driven element with respect to the reflectors and directors
c)
C. The power radiated in the major radiation lobe compared to the power radiated in exactly the opposite direction
d)
D. The ratio of forward gain to dipole gain
8.
G9C08 What is meant by the "main lobe" of a directive antenna?
a)
A. The magnitude of the maximum vertical angle of radiation
b)
B. The point of maximum current in a radiating antenna element
c)
C. The maximum voltage standing wave point on a radiating element
d)
D. The direction of maximum radiated field strength from the antenna
9.
G9C09 How does the gain of two 3-element horizontally polarized Yagi antennas spaced vertically 1/2 wavelength apart typically compare to the gain of a single 3-element Yagi?
a)
A. Approximately 1.5 dB higher
b)
B. Approximately 3 dB higher
c)
C. Approximately 6 dB higher
d)
D. Approximately 9 dB higher
10.
G9C10 Which of the following is a Yagi antenna design variable that could be adjusted to optimize forward gain, front-to-back ratio, or SWR bandwidth?
a)
A. The physical length of the boom
b)
B. The number of elements on the boom
c)
C. The spacing of each element along the boom
d)
D. All of these choices are correct
11.
G9C11 What is the purpose of a gamma match used with Yagi antennas?
a)
A. To match the relatively low feed point impedance to 50 ohms
b)
B. To match the relatively high feed point impedance to 50 ohms
c)
C. To increase the front-to-back ratio
d)
D. To increase the main lobe gain
12.
G9C12 Which of the following is an advantage of using a gamma match for impedance matching of a Yagi antenna to 50 ohm coax feed line?
a)
A. It does not require that the elements be insulated from the boom
b)
B. It does not require any inductors or capacitors
c)
C. It is useful for matching multiband antennas
d)
D. All of these choices are correct
13.
G9C13 Approximately how long is each side of the driven element of a quad antenna?
a)
A. 1/4 wavelength
b)
B. 1/2 wavelength
c)
C. 3/4 wavelength
d)
D. 1 wavelength
14.
G9C14 How does the forward gain of a two-element quad antenna compare to the forward gain of a three-element Yagi antenna?
a)
A. About 2/3 as much
b)
B. About the same
c)
C. About 1.5 times as much
d)
D. About twice as much
15.
G9C15 Approximately how long is each side of the reflector element of a quad antenna?
a)
A. Slightly less than 1/4 wavelength
b)
B. Slightly more than 1/4 wavelength
c)
C. Slightly less than 1/2 wavelength
d)
D. Slightly more than 1/2 wavelength
16.
G9C16 How does the gain of a two-element delta-loop beam compare to the gain of a two-element quad antenna?
a)
A. 3 dB higher
b)
B. 3 dB lower
c)
C. 2.54 dB higher
d)
D. About the same
17.
G9C17 Approximately how long is each leg of a symmetrical delta-loop antenna?
a)
A. 1/4 wavelength
b)
B. 1/3 wavelength
c)
C. 1/2 wavelength
d)
D. 2/3 wavelength
18.
G9C18 What happens when the feed point of a quad antenna of any shape is moved from the midpoint of the top or bottom to the midpoint of either side?
a)
A. The polarization of the radiated signal changes from horizontal to vertical
b)
B. The polarization of the radiated signal changes from vertical to horizontal
c)
C. There is no change in polarization
d)
D. The radiated signal becomes circularly polarized
19.
G9C19 How does antenna gain stated in dBi compare to gain stated in dBd for the same antenna?
a)
A. dBi gain figures are 2.15 dB lower then dBd gain figures
b)
B. dBi gain figures are 2.15 dB higher than dBd gain figures
c)
C. dBi gain figures are the same as the square root of dBd gain figures multiplied by 2.15
d)
D. dBi gain figures are the reciprocal of dBd gain figures + 2.15 dB
20.
G9C20 What is meant by the terms dBi and dBd when referring to antenna gain?
a)
A. dBi refers to an isotropic antenna, dBd refers to a dipole antenna
b)
B. dBi refers to an ionospheric reflecting antenna, dBd refers to a dissipative antenna
c)
C. dBi refers to an inverted-vee antenna, dBd refers to a downward reflecting antenna
d)
D. dBi refers to an isometric antenna, dBd refers to a discone antenna
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