28 4-35.   Which of the following radiation patterns is/are exhibited by a simple vertical doublet antenna? 1.   Nondirectional in the horizontal plane 2.   Directional in the vertical plane 3.   Both 1 and 2 above 4.   Spherical in all planes 4-36.   A method of feeding energy to a half- wave antenna is to connect one end through a capacitor to the output stage.   What is this method of feeding called? 1.   End feed 2.   Voltage feed 3.   Both 1 and 2 above 4.   Current feed 4-37.   An antenna supplied by the center-feed method is fed at what point? 1.   Low voltage and low current 2.   Low voltage and high current 3.   High voltage and low current 4.   High voltage and high current 4-38.   The basic Marconi antenna has which of the following characteristics? 1.   One-quarter wavelength and ungrounded 2.   One-half wavelength and grounded at one end 3.   One-half wavelength and insulated from ground 4.   One-quarter wavelength and grounded at one end 4-39.   The Marconi antenna behaves as a dipole for which of the following reasons? 1.   It is fed at one end 2.   An image antenna is formed by reflections from the ground 3.   A quarter-wavelength of conductor is buried in the ground and forms the rest of the dipole 4.   The applied signal is rectified so that only half the signal will appear on the quarter-wave antenna 4-40.   A series of conductors arranged in a radial pattern and buried in the ground beneath the antenna is referred to as a 1.   ground spur 2.   counterpoise 3.   ground screen 4.   ground reflector 4-41.   A folded dipole can be used instead of a simple, center-fed dipole for which of the following purposes? 1.   Matching voltage 2.   Matching impedance 3.   Increasing directivity 4.   Decreasing directivity 4-42.   An antenna arrangement that has elements aligned in a straight line is referred to as what type array? 1.   Isotropic 2.   Collinear 3.   Line-of-sight 4.   Unidirectional 4-43.   To have current in two adjoining collinear half-wave elements in proper phase, they must be connected by which of the following stubs? 1.   A shorted half-wave stub 2.   An open quarter-wave stub 3.   A shorted eighth-wave stub 4.   A shorted quarter-wave stub 4-44.   To select a desired signal and discriminate against interfering signals, the receiving antenna should have which of the following characteristics? 1.   Be omnidirectional 2.   Be highly directional 3.   Be vertically polarized 4.   Be horizontally polarized