Page:Electronics Technician - Volume 7 - Antennas and Wave Propagation - NAVEDTRA 14092.pdf/111

2-12. A transmitting antenna at ground level should be polarized in what manner to achieve best signal strength?

1. Horizontally
2. Vertically
3. Circularly
4. Linearly

2-13. What term describes the distance a wave travels during the period of one cycle?

1. Wavelength
2. Frequency
3. Travel time
4. Radiation rate

IN ANSWERING QUESTIONS 2-14 AND 2-15, REFER TO FIGURE 2-4 OF THE TEXT.

2-14. The points of high current and voltage are best described by which of the following terms?

1. Peaks
2. Crescents
3. Loops
4. Highs

2-15. The points of minimum voltage and minimum current are represented by which of the following terms?

1. Lows
2. Valleys
3. Descents
4. Nodes

2-16. An antenna at resonance will transmit at maximum efficiency; an antenna that is not at resonance will lose power in which of the following ways?

1. Skin effect loss
2. Heat loss
3. Ground absorption
4. Wave scattering

2-17. An antenna that radiates energy in all directions is said to have what type of radiation pattern?

1. Isotropic
2. Anisotropic
3. Bysotropic
4. Circumstropic

2-18. An antenna that radiates energy more strongly in one direction than another is said to have what type of radiation pattern?

1. Isotropic
2. Anisotropic
3. Bysotropic
4. Circumstropic

2-19. When viewing a radiation pattern graph, you can expect the areas of maximum and minimum radiation be identified by which of the following terms?

1. High and low probes
2. Maximum and minimum points
3. Major and minor lobes
4. Positive and negative lobes

2-20. If an antenna. is too short for the wavelength being used, what electrical compensation must be introduced for the antenna to achieve resonance?

1. Lumped resistance
2. Lumped capacitive reactance
3. Lumped inductive reactance
4. More power

2-21. If an antenna is too long for the wavelength being used, what electrical compensation must be introduced for the antenna to achieve resonance?

1. Lumped resistance
2. Lumped capacitive reactance
3. Lumped inductive reactance
4. Less power

2-22. A ground screen is a series of conductors buried 1 or 2 feet below the surface in a radial pattern and is usually of what length in comparison to the wavelength being used?

1. One-quarter wavelength
2. One-half wavelength
3. Three-quarter wavelength
4. Full wavelength

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