NAVEDTRA 14180A, NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES, MODULE 8-AMPLIFIERS Flashcards
Which term that describes the size of a signal?
Amplitude
Which type of device enables an input signal to control an output signal?
Amplifier
Which standard block diagram symbol is used for an amplifier?
Triangle
Which two ways can most amplifiers be classified?
Function or Frequency response
What is an amplifier in which the output signal voltage is larger than the input signal voltage?
Voltage amplifier
What is an amplifier in which the output signal power is greater than the input signal power?
Power amplifier
Audio amplifier, RF amplifier, along with what else are the three broad categories of frequency response for amplifiers?
Video amplifier
An audio amplifier is designated to amplify frequencies between 15 Hz and what?
20 kHz
RF amplifiers are designed to amplify frequencies between 10kHz and what?
100,000 MHz
A video amplifier is an amplifier designed to amplify a band of frequencies from 10 Hz to what?
6 MHz
How many classes of operation for an amplifier are there?
Four
Which class of amplifier has the characteristics of good fidelity and low efficiency?
Class A
Which term means that the output signal is just like the input signal in all respects except amplitude?
Fidelity
What is any undesired change in a signal from input to output?
Distortion
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?
Class AB
Which type of amplifier has the worst fidelity?
Class C
What is the process known as of transferring energy between circuits?
Coupling
What is the most commonly used coupling in amplifiers?
RC Coupling
What is caused by a small part of the signal from the amplifier output being sent back to the input of the amplifier?
Oscillation
What is the process of sending part of the output signal of an amplifier back to the input of the amplifier called?
Feedback
What is accomplished by adding part of the output signal in phase with the input signal?
Positive feedback
What is accomplished by adding part of the output signal out of phase with the input signal?
Negative feedback
An audio amplifier has been described as an amplifier with a frequency response from 15 Hz to what?
20 kHz
Which type of device produces two signals that differ in phase from each other from a single input signal?
Phase splitter
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?
Push-pull
Which type of amplifier can have two input signals and/or two output signals?
Differential
Which type of amplifier can add, subtract, multiply, divide, and even perform the calculus operations of integration and differentiation?
Operational
How many outputs can the differential amplifier have?
Two
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?
Operational
How many stages are there within the operational amplifier?
Three
A typical operational amplifier could have a voltage gain of what?
200,000
Which type of operation does the operational amplifier have without feedback?
Open-loop
What is a point in a circuit which is at ground potential (0 volts) but is NOT connected to ground?
Virtual ground
What will always produce an output that is equal to the sum of the input signals but opposite in polarity?
Adder circuit
What property of the circuit is determined by the ratio between the feedback resistor and the input resistors?
Gain
Which circuit multiplies each input by a factor (the factor is determined by circuit design) and then adds these values together?
Scaling amplifier
That magnetic amplifier has very high efficiency (up to what percent)?
90
What does the magnetic amplifier use to amplify a signal?
Electromagnetism
What is defined as the measure of the ability of a material to act as a path for additional magnetic lines of force?
Permeability
What is defined as the number of lines of force passing through a given area?
Flux density
What is the magnetomotive force developed by 1 ampere of current flowing in a coil of one turn called?
Ampere-turn
What is a magnetic-core reactor (coil) whose reactance is controlled by changing the permeability of a core?
Saturable-core reactor
What is the point of maximum curvature on a magnetization curve?
Knee of the curve
What does a magnetic amplifier have in addition to a saturable-core reactor?
Rectifier
What is the general symbol for an amplifier?
Triangle
Magnetic amplifiers are power amplifiers with a frequency response normally limited to what or below?
100 hertz
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?
Bias winding