NAVEDTRA 14182A, NEETS Mod. 10, Ch. 3 Flashcards Preview

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Flashcards in NAVEDTRA 14182A, NEETS Mod. 10, Ch. 3 Deck (19):
1

Which device is designed to guide electrical energy from one point to another?

Transmission line

2

Which type of line is most often used for power lines, rural telephone lines, and telegraph lines?

Two-wire open line

3

Which type of line consists of two insulated wires twisted together to form a flexible line without the use of spacers?

Twisted pair

4

Leakage caused by the condensation of moisture is prevented in some rigid line applications by the use of what?

Inert gas

5

What was developed to replace rubber and eliminate high-frequency losses associated with rubber insulators?

Polyethylene plastic

6

The radius of bends in the waveguide must measure greater than how many wavelengths at the operating frequency of the equipment to avoid excessive attenuation?

Two

7

Line losses may be any of three types— Radiation/Induction, Dielectric, and what else?

Copper

8

Copper losses can be minimized and conductivity increased in an RF line by plating the line with what?

Silver

9

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

10

What determines the amount of current that can flow when a given voltage is applied to an infinitely long line?

Characteristic impedance

11

The characteristic impedance of lines in actual use normally lies between 50 and how many ohms?

600

12

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

13

If a line is not terminated in characteristic impedance, what is it said to be?

Finite

14

What are voltages called that are moving toward the receiving end of a line?

Incident voltages

15

Which type of line has no standing waves of current and voltage?

Nonresonant

16

Which type of line has a finite length and is not terminated in its characteristic impedance?

Resonant

17

What is the ratio of maximum voltage to minimum voltage on a line called?

VSWR

18

What are hollow metal tubes used to transfer energy from one point to another?

Waveguides

19

What are theoretical properties (inductance, resistance, and capacitance) of a transmission line that are lumped into a single component? 


Lumped constants