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A comprehensive set of questions and answers related to ac motors and generators, covering topics such as their operation, types, and applications. It is a valuable resource for students studying electrical engineering or related fields, offering insights into the fundamental principles and practical aspects of these essential components.
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Why is the AC motor the most popular type of rotating machinery used? ---- -----CORRECT ANSWER-----------------AC power is readily available What valve provide reversal of the fluid flow? ---------CORRECT ANSWER-- ---------------Rotary spoil and 4 way sliding spool What term is used to describe speed in a motor or generator? --------- CORRECT ANSWER-----------------RPM What are two general categories of rotating machinery? ---------CORRECT ANSWER-----------------Generators and motors Mechanical energy is provided by what? ---------CORRECT ANSWER-------- ---------Prime mover What is a symptom of relief valve stuck in the closed position? --------- CORRECT ANSWER-----------------Overheated pump Which rotary positive displacement pump has the shortest life expectancy? ---------CORRECT ANSWER-----------------Internal gear
What is the term used to describe the action of starting and stopping stepper motors slower than the running speed? ---------CORRECT ANSWER-----------------EFSS What does an AC motor need as an electrical input signal? --------- CORRECT ANSWER-----------------AC;Sine wave Which type of AC motor is normally used in either large horsepower or special application devices? ---------CORRECT ANSWER----------------- Synchronous What is checking and changing the fluid level in the reservoir recommended? ---------CORRECT ANSWER-----------------To check viscosity In an AC generator the output voltage across the load in the external circuit reverses polarity with every what rotation? ---------CORRECT ANSWER----- ------------180 degree What principle of magnetism do motors operate on? ---------CORRECT ANSWER-----------------Attraction and repulsion What principle of magnetism do generators operate on? ---------CORRECT ANSWER-----------------Producing voltage; passing a conductor through a magnetic field
What type of positive displacement pump is used in most hydraulic systems? ---------CORRECT ANSWER-----------------Rotary What are the basic components of a synchro? ---------CORRECT ANSWER-----------------Stator and rotor Which device in the control synchro system performs the same function as the torque transmitter? ---------CORRECT ANSWER-----------------Control transmitter What do valves control? ---------CORRECT ANSWER----------------- Direction,pressure,flow, Velocity and isolation What can a technician go to troubleshoot a signal path with a signal that is too low for an O-Scope? ---------CORRECT ANSWER-----------------Insert a signal with a function generator When should water be used in a Hydraulic system? ---------CORRECT ANSWER-----------------NEVER What is position ---------CORRECT ANSWER-----------------Location of an object
What would you use a multimeter for trouble shooting a synchro system? -- -------CORRECT ANSWER-----------------Resistance PID stabilization is reached as what refuse the overshoot of the signal? ----- ----CORRECT ANSWER-----------------Derivative; Control mode The flow control valve is used to? ---------CORRECT ANSWER----------------- Regulate speed of the actuator (PID) What is the condition which indicates the values of a circuit have settled and tend to remain constant? ---------CORRECT ANSWER------------- ----Steady state (PID) What is the optimum operating parameter or a reference to which an operator adjusts the process of optimum operation? ---------CORRECT ANSWER-----------------Set point What is the sequence for energizing the stator shoe a clockwise pattern? -- -------CORRECT ANSWER-----------------A,B,A w/ hat,B w/ hat The piston compressor is one type of ---------CORRECT ANSWER------------ -----Displacement compressor What term is used to describe the highest PPS a stepper motor can use? -- -------CORRECT ANSWER-----------------Slew Rate (Sr)
A rotating device for converting mechanical energy into an alternating electrical energy. ---------CORRECT ANSWER-----------------generator Three basic sine wave characteristics: ---------CORRECT ANSWER---------- -------frequency, period, and wavelength One cycle of AC always consists of ______________. ---------CORRECT ANSWER-----------------two alterations A unit of measure for frequency. ---------CORRECT ANSWER----------------- Hertz _________ is the number of complete cycles occurring in one second. ------ ---CORRECT ANSWER-----------------frequency The time it takes for a sine wave to complete one cycle. ---------CORRECT ANSWER-----------------period The actual distance between the beginning and end of one AC sine wave cycle. ---------CORRECT ANSWER-----------------wavelength AC current flows from ______________. ---------CORRECT ANSWER------- ----------negative to positive
The magnetic or electric effect of one body on another without any physical contact between them. ---------CORRECT ANSWER-----------------induction A magnetic field is composed of magnetic lines of _______. --------- CORRECT ANSWER-----------------flux The direction of the flux lines is from the _______ Pole to the _______ Pole. ---------CORRECT ANSWER-----------------north, south The action of a conductor moving through a magnetic field causing current flow. ---------CORRECT ANSWER-----------------electromagnetic induction The effective value of an AC voltage that causes the same amount of power dissipation as a specific DC voltage. ---------CORRECT ANSWER---- -------------RMS ______ isthe relative position of AC quantities in time reference to each other. ---------CORRECT ANSWER-----------------phase RC transients occur when the _______ across a capacitor changes. --------- CORRECT ANSWER-----------------voltage
When the inductive and capacitive reactances are equal, an LCR circuit is __________. ---------CORRECT ANSWER-----------------resonant A __________ circuit is one in which the capacitive reactance equals the inductive reactance. (Xc=Xl) ---------CORRECT ANSWER----------------- resonant A ________ component in a parallel resonant circuit is indicated by the branch current measures maximum. ---------CORRECT ANSWER------------- ----shorted In an inductive, capacitive, and resistive (LCR) circuit, _________ oppose current at 180 degrees. - --------CORRECT ANSWER-----------------Xl and Xc In a SERIES LCR circuit, when Xc is larger than Xl the circuit is ________. ---------CORRECT ANSWER-----------------capacitive In a PARALLEL LCR circuit, when Xc is larger than Xl the circuit is _________. ---------CORRECT ANSWER-----------------inductive In a PARALLEL resonant circuit that has an OPEN inductor, the voltage drop across the sampling resistor, Rs, ___________________. --------- CORRECT ANSWER-----------------decreases below the resonance The output of a transformer is taken from the _________. --------- CORRECT ANSWER-----------------secondary
The most common faults found in transformers are ___________. --------- CORRECT ANSWER-----------------opens and shorts An OPEN in the PRIMARY of a transformer causes no output voltage because the OPEN ____________________. ---------CORRECT ANSWER-----------------prevents magnetic fields from developing in the primary The N indicates what in the Identification number? ---------CORRECT ANSWER-----------------solid state device The cathode of a diode is represented by _________. ---------CORRECT ANSWER-----------------a bar N type material has _______________. ---------CORRECT ANSWER--------- --------free electrons P type material has _________. ---------CORRECT ANSWER----------------- holes The anode of a diode is represented by ___________. ---------CORRECT ANSWER-----------------an arrow
What is localization used for? ---------CORRECT ANSWER----------------- Determine what section is faulted What type of power is produced by a generator? ---------CORRECT ANSWER-----------------AC & DC What type of acceleration is fixed between two points? ---------CORRECT ANSWER-----------------Linear What happens to the velocity of fluid in a flowing pipe if pressure decreases? ---------CORRECT ANSWER-----------------Velocity decreases A device that has a spinning shaft and uses electricity as the input or output is called ---------CORRECT ANSWER-----------------Rotating Machinery In a pneumatic pump what provided rotary pump cooling and lubrication? -- -------CORRECT ANSWER-----------------Reservoir gas The sight glass on a reservoir measures the amount of what? --------- CORRECT ANSWER-----------------Hydronic fluid What are two classifications of synchros? ---------CORRECT ANSWER------ -----------Control and Torque
When adjusting the rod on a flow control valve you are in essence changing what in regards to the pipe? ---------CORRECT ANSWER----------- ------Diameter Which pump provides the longest life in a typical hydraulic system? --------- CORRECT ANSWER-----------------Lube pump