CDC 3D153 Volume 2 V2 (April 2013)
CDC 3D153 01 1206, Edit Code 02 (April 2013) Volume 2 Units 1-5 Unit 1: Antenna Theory Unit 2: Electromagnetic Wave Theory Unit 3: Transmission Security Techniques, Data Linking Concepts and Jam-Resistant Communications Unit 4: Other RF Transmission Systems Unit 5: High Frequency Communications
- 1.Equipment used for generating, amplifying, and transmitting RF carrier is collectively called
- A.
A receiver.
- B.
An antenna.
- C.
A transmitter.
- D.
A transmission line.
- 2.What basic receiver function involves having the transmitted electromagnetic wave pass through the receive antenna in such a manner as to induce a voltage in the antenna?
- A.
Reproduction.
- B.
Reception.
- C.
Detection.
- D.
Selection.
- 3.The ability of a receiver to reproduce the signal of a very weak station is the characteristic of the receiver’s
- A.
Fidelity.
- B.
Capacity.
- C.
Sensitivity.
- D.
Selectivity.
- 4.The ability to reproduce the input signal accurately is the characteristics of the receiver’s
- A.
Fidelity.
- B.
Capacity.
- C.
Sensitivity.
- D.
Selectivity.
- 5.Which of the following CANNOT be performed by the transceiver’s computerized components and micro-circuitry?
- A.
Specific equipment faults.
- B.
Internal equipment tests.
- C.
Internal calibrations.
- D.
Repair itself.
- 6.Resistance of the conductor material in a transmission line leads to which type of loss?
- A.
Copper.
- B.
Radiation.
- C.
Inductive.
- D.
Skin-effect.
- 7.Leakage loss in a transmission line can be minimized by using a
- A.
Thinner conductor.
- B.
Thicker conductor.
- C.
Very low-resistance dielectric.
- D.
Very high-resistance dielectric.
- 8.A transmission line that consists of a center conductor placed inside a rigid metal tube functioning as the outer tube is called a
- A.
Flexible coaxial cable.
- B.
Rigid coaxial cable.
- C.
Waveguide.
- D.
Twin lead.
- 9.Which statement concerning waveguides is FALSE?
- A.
Very slight damage to the external surface of a waveguide can cause arcing.
- B.
Their conductive material construction is easily dented.
- C.
Effectiveness of waveguides is hindered by moisture.
- D.
Waveguides can be destroyed by corrosion.
- 10.What two properties of a transmission line determine its characteristic impedance?
- A.
Inductance and resistance.
- B.
Inductance and capacitance.
- C.
Resistance and capacitance.
- D.
Length and type of shielding.
- 11.Using figure 1–10, determine the electrical length if the frequency is changed from 150 MHz to 250 MHz.
- A.
8.33 meters.
- B.
8.33 wavelengths.
- C.
83.3 meters.
- D.
83.3 wavelengths.
- 12.Which statement concerning line lengths is TRUE?
- A.
Frequency and electrical length are inversely proportional.
- B.
Frequency and physical length are directly proportional.
- C.
With constant physical length, frequency and electrical length are directly related.
- D.
With constant physical length, frequency and electrical length are inversely related.
- 13.A nonresonant transmission line is a line
- A.
Having reflected waves.
- B.
Having no reflected waves.
- C.
With maximum voltage across its open termination.
- D.
With maximum voltage across its shorted termination.
- 14.If a transmission line is terminated in an open, what will likely result?
- A.
Signal loss would be negligible.
- B.
There would be significant signal loss.
- C.
Current would be at maximum at the termination.
- D.
Voltage would be at minimum at the termination.
- 15.The concept that alternating current changes in magnitude and reverses its direction during each cycle is
- A.
An unproven hypothesis.
- B.
The definition of propagation.
- C.
What makes radio transmission possible.
- D.
What led to the discovery of direct current.
- 16.At what point do magnetic fields around a wire no longer have time to collapse completely between alternations?
- A.
60 cycles per second (cps).
- B.
120 cps.
- C.
10,000 cps.
- D.
15,000 cps.
- 17.Which basic field detaches from the antenna and travels through space at great distances?
- A.
Radiation.
- B.
Induction.
- C.
Gravitational.
- D.
Electromotive.
- 18.Areas in which no antenna radiation pattern passes through are called
- A.
Nulls.
- B.
Lobes.
- C.
Free space.
- D.
Nonresonant.
- 19.If the electric field component travels in a plane perpendicular to the Earth’s surface, the radio wave is considered to be polarized
- A.
Magnetically.
- B.
Horizontally.
- C.
Circularly.
- D.
Vertically.
- 20.The actual range of frequencies within the antenna’s bandwidth is called the
- A.
Wavelength.
- B.
Operating zone.
- C.
Frequency range.
- D.
Bandwidth range.
- 21.What measurement is used to determine whether an antenna is resonant at a particular frequency?
- A.
Distortion.
- B.
Standing wave ratio.
- C.
Signal-to-noise ratio.
- D.
Percent of modulation.
- 22.The ability of an antenna to both receive and transmit equally well is known as the antenna’s
- A.
Bandwidth.
- B.
Resonance.
- C.
Reciprocity.
- D.
Effectiveness.
- 23.The standard used to measure the radiating effectiveness (gain) of an antenna system is the
- A.
Marconi antenna.
- B.
Isotropic antenna.
- C.
Hertz antenna.
- D.
Whip antenna.
- 24.What does the overall effectiveness of an entire transmitting and receiving system depend largely upon?
- A.
Impedance matching.
- B.
Antenna distance.
- C.
Antenna properties.
- D.
Line characteristics.
- 25.Which antenna radiates radio energy equally well in all directions?
- A.
Omni-directional.
- B.
Uni-directional.
- C.
Bi-directional.
- D.
Directional.
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