Online Questions and Answer Topic Outline
- MCQs in Basic considerations
- MCQs in Wire Radiators in Space
- MCQs in Isotropic Radiator
- MCQs in Current and Voltage Distributions
- MCQs in Resonant and Non-resonant Antennas
- MCQs in Antenna Terms and Definition
- MCQs in Antenna Gain and Resistance
- MCQs in Bandwidth, Beamwidth and Polarization
- MCQs in Grounded and Ungrounded Antennas
- MCQs in Grounding Systems and Matching Systems
- MCQs in Antenna Types
- MCQs in Directional and Non-directional Antennas
- MCQs in Microwave Antennas
- MCQs in Wideband and Special Purpose Antennas
MCQs in Antennas Series
Following is the list of multiple choice questions in this brand new series:
Continue Practice Exam Test Questions Part III of the Series
101. Stacking antenna elements
- A. increases sensitivity to weak signals
- B. will suppress odd harmonics
- C. decrease signal to noise ratio
- D. increases selectivity
102. In the case if Marconi antenna, the actual length if the radiating element is
- A. one-half wavelength
- B. one-quarter wavelength
- C. one wavelength
- D. one-eight wavelength
103. The antenna efficiency of an HF grounded vertical antenna can be made comparable to that of a half-wave antenna
- A. By installing a good ground radial system
- B. By isolating the coax shield from ground
- C. By shortening the vertical
- D. By lengthening the vertical
104. An antenna “efficiency” is computed by using one of the following equations.
- A. Efficiency = (radiation resistance / transmission resistance)
- B. Efficiency = (total resistance / radiation resistance) x 100%
- C. Efficiency = (effective radiated power / transmitter output) x 100%
- D. Efficiency = (radiation resistance / total resistance) x 100%
105. Increasing the resonant frequency of an end-fed Marconi antenna can be done by
- A. adding a capacitor in series and reducing the physical length
- B. adding an inductor in series
- C. adding an inductor in series
- D. All of these
106. Factors that determine the radiation resistance of an antenna
- A. Transmission line length and height of antenna
- B. The location of the antenna with respect to nearby objects
- C. It is a constant for all antennas since it is physical
- D. Sunspot activity and the time of day
107. _____ is the angle between the half-power radiation points
- A. Critical angle
- B. Beamwidth
- C. Angle of elevation
- D. Azimuth
108. What is the ratio of the maximum radiation intensity to the average radiation intensity?
- A. Aperture gain
- B. Directivity gain
- C. Transmission gain
- D. Power gain
109. Good grounding is important for
- A. horizontal antennas
- B. broadside array antennas
- C. vertical antennas
- D. Yagi-Uda antennas
110. An ungrounded antenna near the ground
- A. acts as a single antenna of twice the height
- B. is unlikely to need an earth mat
- C. acts as antenna array
- D. must be horizontally polarized
111. One of the following is very useful as a multiband HF receiving antenna.
- A. Parabolic antenna
- B. Elementary doublet
- C. Log-periodic
- D. Square loop
112. Which of the following antennas is best excited from a waveguide?
- A. Biconical
- B. Horn
- C. Helical
- D. Discone
113. Indicate which of the following reasons for using metal counterpoise with antennas is false.
- A. Impossibly of a good ground connection
- B. Protection of personnel working underneath
- C. Provision of an earth for the antenna
- D. Rockiness of the ground itself
114. Not a reason for the use of an antenna coupler.
- A. To make the antenna look resistive
- B. To provide the output amplifier with the correct load impedance
- C. To discriminate against harmonics
- D. To prevent re-radiation of the local oscillator
115. Which antenna is not a wideband?
- A. Discone
- B. Folded dipole
- C. Helical
- D. Marconi
116. One of the following is not a reason for the use of an earth mat
- A. impossibility of a good ground connection
- B. provision of an earth for the antenna
- C. protection of personnel working underneath
- D. improvement of the radiation pattern of the antenna
117. One of the following makes an antenna physically long but electrically short
- A. Adding L in series
- B. Adding C in series
- C. Top loading
- D. Both A and C
118. When antennas are closed to the ground, _______ polarization is ideal
- A. horizontally polarized
- B. vertically polarized
- C. circularly polarized
- D. both A and B
119. _____ is an antenna made up of a number of full wavelengths
- A. Elementary doublet
- B. Log-periodic
- C. Long wire
- D. Whip
120. Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc.
- A. Radiant energy
- B. Electromagnetic
- C. Heat
- D. Ultraviolet
121. Which one is an antenna coupling unit?
- A. Coupler
- B. Diplexer
- C. Lecher wire
- D. Duplexer
122. _____ polarization is employed in AM broadcasting
- A. Horizontal
- B. Vertical
- C. Circular
- D. Omnidirectional
123. ______ polarization is employed in FM broadcasting
- A. Horizontal
- B. Vertical
- C. Circular
- D. Bidirectional
124. Which antenna is not grounded at one end?
- A. Hertz
- B. Marconi
- C. Dipole
- D. Whip
125. Which antenna does not use the ground?
- A. Marconi
- B. Yagi
- C. Hertz
- D. Rhombic
126. Class of citizens band station operating at 462.55 to 466.45 MHz.
- a. Class A
- b. Class B
- c. Class C
- d. Class D
127. Ground system recommended by the FCC for broadcast stations consists of a minimum of _______.
- a. 120 radials
- b. 150 radials
- c. 130 radials
- d. 140 radials
128. To achieve maximum possible energy transfer between transmitting and receiving stations at practical distances, _______ are used.
- a. High gain
- b. Parabolic reflector
- c. Director
- d. secret
129. ________ is the transmission of data metered at a distance from the observer.
- a. Data communications
- b. Altimetery
- c. Telemetry
- d. cemetery
130. Impedance transformation between a balanced and unbalanced impedances.
- a. Gamma match
- b. Eslun transformer
- c. Decca match
- d. Match box
131. Calculate the physical length required of a 146 MHz 4:1 balun mode of polyethylene foam coaxial cable. Use velocity factor of 0.80.
- a. 12.6 ft
- b. 2.5 m
- c. 32.4 inches
- d. 6.2 inches
132. _______ is an instrument that measures the radiated field from an antenna.
- a. Field strength meter
- b. Field meter
- c. Strength meter
- d. Intensity meter
133. Calculate the number of turns required to make a 5 uH inductor on a t-50-6 core. Use core factor AL of 40.
- a. 25
- b. 35
- c. 45
- d. 50
134. This resistance is a hypothetical concept that accounts for the fact that rF power is radiated by the antenna.
- a. Ohmic resistance
- b. Resistance
- c. Radiation resistance
- d. None of these
135. If 1000 watts of RF power is applied to the feedpoint, and a current of 3.7 amperes was measured, what is the radiation resistance?
- a. 50 ohms
- b. 300 ohms
- c. 600 ohms
- d. 73 ohms
136. Antenna theory recognizes a point of reference called the _________.
- a. Half-wave dipole
- b. Full wave dipole
- c. Isotropic radiator
- d. Image antenna
137. Quarter wavelength vertical antenna is basically a dipole placed vertically, with the other half of the dipole being the ____________.
- a. Gain
- b. Radials
- c. Ground
- d. Reflector
138. Most common form of multi-band wire antenna is the __________.
- a. Log periodic antenna
- b. Yagi Uda
- c. Long wire antenna
- d. Trap dipole
139. The change in velocity resulting from a stray capacitance is called _________.
- a. End effect
- b. Skin effect
- c. Proximity effect
- d. No effect
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