








Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
A collection of questions and answers related to ac/dc circuits and electronics, covering fundamental concepts like alternating current, generators, transformers, diodes, and basic circuit analysis. It is a valuable resource for students studying electrical engineering or related fields, offering a comprehensive overview of key topics and their applications.
Typology: Exams
1 / 14
This page cannot be seen from the preview
Don't miss anything!
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 devices are affected by a shorted stator winding on a transmitter? ---- -----CORRECT ANSWER-----------------All of them What device reduces noise and redirects the air stream so it will not cause any injuries? ---------CORRECT ANSWER-----------------The muffler What does the fluid provide to the rotary pump in a hydraulic system? ------- --CORRECT ANSWER-----------------Lubrication and cooling
What is the major difference between the torque synchro system and the control synchro system? ---------CORRECT ANSWER----------------- Control=dry signal= synchro system What is the relationship between distance and time when solving for velocity? ---------CORRECT ANSWER-----------------🔺D / 🔺T Worn packing in a pump causes ---------CORRECT ANSWER----------------- Leaks What principle of magnetism allows a generator to power its own stator windings and still generate an output voltage? ---------CORRECT ANSWER-----------------Retentivity How does an incremental motor operate? ---------CORRECT ANSWER------ -----------Specific differences for each 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
(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) What is the purpose of the synchro system? ---------CORRECT ANSWER--- --------------Transfer angular info in form of voltage What is a major benefit of positive displacement pumps? ---------CORRECT ANSWER-----------------Self priming What uses the system pressure to perform the work either through linear motion or rotary motion ---------CORRECT ANSWER-----------------Actuator
What is best used to locate a suction leak on a hydraulic system? --------- CORRECT ANSWER-----------------Eye dropper filled with hydraulic fluid How does a continuous motor operate? ---------CORRECT ANSWER--------- --------Rotates without interruption when input is applied An electrical current that changes both in magnitude and direction. --------- CORRECT ANSWER-----------------alternating current AC is developed by sources called _____________. ---------CORRECT ANSWER-----------------alternators and generators A device which converts mechanical energy into an alternating electrical current. ---------CORRECT ANSWER-----------------alternator 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
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 What is the phase relationship between voltage and current through an inductor? ---------CORRECT ANSWER-----------------voltage leads current by 90 The currents developed by an inductor and a capacitor are 180 degrees apart in phase, their reactance: ---------CORRECT ANSWER----------------- opposes each other What is the phase relationship between current through a capacitor and an inductor? ---------CORRECT ANSWER-----------------currents are 180 apart
When the capacitor is fully charged; Ec (voltage) is the maximum and Ic (current) is ________ ---------CORRECT ANSWER-----------------minimum The relationship between frequency and the RC time constant is the principle of _______________. ---------CORRECT ANSWER----------------- capacitive reactance In a PARALLEL circuit LCR, an _____________component is recognized by no current flow in that branch ---------CORRECT ANSWER----------------- open The effect of a _______________ component in a series circuit LCR causes all voltage drops to be incorrect. ---------CORRECT ANSWER-------- ---------changed value 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
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 How is a battery connected to foward bias a diode? ---------CORRECT ANSWER-----------------the negative side to the cathode, the positive side to the anode The primary characteristic of the diode can be described as _________________________. ---------CORRECT ANSWER----------------- changing AC current flow to DC current flow When foward biased the diode acts as a ___________. ---------CORRECT ANSWER-----------------closed switch
Resistance readings for a _________ diode indicate low resistance. --------- CORRECT ANSWER-----------------shorted A diode measuring low resistance in one direction and high in the other indicates _________________. ---------CORRECT ANSWER----------------- proper diode operation What do motion detector circuits not sense? ---------CORRECT ANSWER--- --------------Position An AC induction motor operates on the principle of what? --------- CORRECT ANSWER-----------------Induction 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
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 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