NAVEDTRA 14188A, NEETS Mod. 16, Ch. 2 Flashcards Preview

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Flashcards in NAVEDTRA 14188A, NEETS Mod. 16, Ch. 2 Deck (25)
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1

What is the product of the potential in volts and the current in amperes?

Watt

2

Power measurements for af circuits are usually indicated in terms of decibels (dB) or decibels referenced to what?

1 milliwatt (dBm)

3

Which type of unit expresses the logarithmic ratio between the input and the output of any given component, circuit, or system?

Bel

4

You can convert any figure expressed in bels to decibels by multiplying that figure by what?

10

5

Which type of loading device undergoes changes of resistance as changes in dissipated power occur?

Bolometer

6

What are the two types of bolometers?

Barretter and Thermistor

7

A thermistor bridge circuit includes other thermistor elements, referred to as what?

Compensating thermistors

8

The rotating frequency (speed in revolutions per minute) of armatures in electric motors and engine-driven generators, as well as the blade speed in turbines, is measured with devices called tachometers, stroboscopes, and what else?

Strobotacs

9

Which type of instrument measures the rate at which a shaft is turning?

Tachometer

10

What are the two common types of portable tachometers?

Centrifugal and Chronometric

11

Which type of instrument allows you to view rotating or reciprocating objects intermittently and produces the optical effect of a slowing down or stopping motion?

Stroboscope

12

Which type of electronic flash device is the flash duration is very short (a few millionths of a second)?

Strobotac

13

Which type of device is the simplest type of frequency meter?

Vibrating-reed

14

What are used as filters for the passage or rejection of specific frequencies?

Tuned circuits

15

Which type of circuit offers a low impedance to currents of the particular frequency to which the circuit is tuned and a relatively high impedance to currents of all other frequencies?

Series-tuned

16

Which type of frequency meters are used to measure the frequency of the unknown signal by matching the unknown signal with a locally generated signal of the same frequency obtained from a calibrated, precision oscillator?

Heterodyne

17

Which calibrated resonant circuits are used to measure frequency?

Wavemeters

18

Which type of wavemeter is the type most commonly used?

Cavity

19

Which high-speed electronic counter has an accurate, crystal-controlled time base?

Electronic frequency counter

20

What is commonly used for the analysis of waveforms generated by electronic equipment?

Cathode-Ray Oscilloscope

21

Which type of device sweeps over a band of frequencies to determine what frequencies are being produced by a specific circuit under test and the amplitude of each frequency component?

Spectrum Analyzer

22

Transistors, however, are capable of operating in excess of how many hours at maximum rating without failure?

30,000

23

What can be used to graphically display the back-and-forward resistance characteristics of a crystal diode?

Oscilloscope

24

Tube failures account for over what percent of the failures in electron-tube equipments?

90

25

Transistors are easily damaged by high current; therefore, resistance measurements must not be taken with an ohmmeter that provides a maximum current output in excess of what?
1 milliampere

Transistors are easily damaged by high current; therefore, resistance measurements must not be taken with an ohmmeter that provides a maximum current output in excess of what?
1 milliampere