NAVEDTRA 14180A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES, MODULE 8-AMPLIFIERS

Question 1

Which term that describes the size of a signal?

Answer 1

Amplitude

Question 2

Which type of device enables an input signal to control an output signal?

Answer 2

Amplifier

Question 3

Which standard block diagram symbol is used for an amplifier?

Answer 3

Triangle

Question 4

Which two ways can most amplifiers be classified?

Answer 4

Function or Frequency response

Question 5

What is an amplifier in which the output signal voltage is larger than the input signal voltage?

Answer 5

Voltage amplifier

Question 6

What is an amplifier in which the output signal power is greater than the input signal power?

Answer 6

Power amplifier

Question 7

Audio amplifier, RF amplifier, along with what else are the three broad categories of frequency response for amplifiers?

Answer 7

Video amplifier

Question 8

An audio amplifier is designated to amplify frequencies between 15 Hz and what?

Answer 8

20 kHz

Question 9

RF amplifiers are designed to amplify frequencies between 10kHz and what?

Answer 9

100,000 MHz

Question 10

A video amplifier is an amplifier designed to amplify a band of frequencies from 10 Hz to what?

Answer 10

6 MHz

Question 11

How many classes of operation for an amplifier are there?

Answer 11

Four

Question 12

Which class of amplifier has the characteristics of good fidelity and low efficiency?

Answer 12

Class A

Question 13

Which term means that the output signal is just like the input signal in all respects except amplitude?

Answer 13

Fidelity

Question 14

What is any undesired change in a signal from input to output?

Answer 14

Distortion

Question 15

Which operating class is the amplifier if the amplifying device is biased in such a way that current flows in the device for 51%-99% of the input signal?

Answer 15

Class AB

Question 16

Which type of amplifier has the worst fidelity?

Answer 16

Class C

Question 17

What is the process known as of transferring energy between circuits?

Answer 17

Coupling

Question 18

What is the most commonly used coupling in amplifiers?

Answer 18

RC Coupling

Question 19

What is caused by a small part of the signal from the amplifier output being sent back to the input of the amplifier?

Answer 19

Oscillation

Question 20

What is the process of sending part of the output signal of an amplifier back to the input of the amplifier called?

Answer 20

Feedback

Question 21

What is accomplished by adding part of the output signal in phase with the input signal?

Answer 21

Positive feedback

Question 22

What is accomplished by adding part of the output signal out of phase with the input signal?

Answer 22

Negative feedback

Question 23

An audio amplifier has been described as an amplifier with a frequency response from 15 Hz to what?

Answer 23

20 kHz

Question 24

Which type of device produces two signals that differ in phase from each other from a single input signal?

Answer 24

Phase splitter

Question 25

Which type of amplifier uses two transistors whose output signals are added together to provide a larger gain (usually a power gain) than a single transistor could provide?

Answer 25

Push-pull

Question 26

Which type of amplifier can have two input signals and/or two output signals?

Answer 26

Differential

Question 27

Which type of amplifier can add, subtract, multiply, divide, and even perform the calculus operations of integration and differentiation?

Answer 27

Operational

Question 28

How many outputs can the differential amplifier have?

Answer 28

Two

Question 29

Which type of amplifier is designed to be used with other circuit components to perform either computing functions (addition, subtraction) or some type of transfer operation, such as filtering?

Answer 29

Operational

Question 30

How many stages are there within the operational amplifier?

Answer 30

Three

Question 31

A typical operational amplifier could have a voltage gain of what?

Answer 31

200,000

Question 32

Which type of operation does the operational amplifier have without feedback?

Answer 32

Open-loop

Question 33

What is a point in a circuit which is at ground potential (0 volts) but is NOT connected to ground?

Answer 33

Virtual ground

Question 34

What will always produce an output that is equal to the sum of the input signals but opposite in polarity?

Answer 34

Adder circuit

Question 35

What property of the circuit is determined by the ratio between the feedback resistor and the input resistors?

Answer 35

Gain

Question 36

Which circuit multiplies each input by a factor (the factor is determined by circuit design) and then adds these values together?

Answer 36

Scaling amplifier

Question 37

That magnetic amplifier has very high efficiency (up to what percent)?

Answer 37

90

Question 38

What does the magnetic amplifier use to amplify a signal?

Answer 38

Electromagnetism

Question 39

What is defined as the measure of the ability of a material to act as a path for additional magnetic lines of force?

Answer 39

Permeability

Question 40

What is defined as the number of lines of force passing through a given area?

Answer 40

Flux density

Question 41

What is the magnetomotive force developed by 1 ampere of current flowing in a coil of one turn called?

Answer 41

Ampere-turn

Question 42

What is a magnetic-core reactor (coil) whose reactance is controlled by changing the permeability of a core?

Answer 42

Saturable-core reactor

Question 43

What is the point of maximum curvature on a magnetization curve?

Answer 43

Knee of the curve

Question 44

What does a magnetic amplifier have in addition to a saturable-core reactor?

Answer 44

Rectifier

Question 45

What is the general symbol for an amplifier?

Answer 45

Triangle

Question 46

Magnetic amplifiers are power amplifiers with a frequency response normally limited to what or below?

Answer 46

100 hertz

Question 47

What allows a d.c. bias voltage to be applied to the saturable-core reactor while a.c. control signals are applied to a separate control winding?

Answer 47

Bias winding