NAVEDTRA 14182A Chapter 3 Flashcards
Which device is designed to guide electrical energy from one point to another?
Transmission line
Which type of line is most often used for power lines, rural telephone lines, and telegraph lines?
Two-wire open line
Which type of line consists of two insulated wires twisted together to form a flexible line without the use of spacers?
Twisted pair
Leakage caused by the condensation of moisture is prevented in some rigid line applications by the use of what?
Inert gas
What was developed to replace rubber and eliminate high-frequency losses associated with rubber insulators?
Polyethylene plastic
The radius of bends in the wave guide must measure greater than how many wave lengths at the operating frequency of the equipment to avoid excessive attenuation?
Two
Line losses may be any of three types - radiation / induction, dielectric and what else?
Copper
Copper losses can be minimized and conductivity increased in an RF line by plating the line with what?
Silver
Which type of losses occur because some magnetic lines of force about a conductor do not return to the conductor when the cycle alternates?
Radiation
What determines the amount of current that can flow when a given voltage is applied to an infinitely long line?
Characteristic impedance
The characteristic impedance of lines in actual use normally lies between 50 and how many ohms?
600
When a transmission line is “short” compared to the length of the radio-frequency waves it carries, the opposition presented to the input terminals is determined primarily by what?
Load impedance
If a line is not terminated in characteristic impedance, what is it said to be?
Finite
What are voltages called that are moving toward the receiving end of a line?
Incident voltages
Which type of line has no standing waves of current and voltage?
Non resonant
