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ATT TEST 11 ACTUAL TEST 2025 | ALL QUESTIONS
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At what points are max flux lines cut and peak volts produced? --------- CORRECT ANSWER-----------------When armature is parallel to lines of force (90 and 270 degrees) What are three types of DC generators? ---------CORRECT ANSWER-------- ---------permanent magnet, separately excited, self-excited What are 3 types of DC motors? ---------CORRECT ANSWER----------------- Series, shunt and compound What is the assumed value of K? ---------CORRECT ANSWER----------------- 1 How are speed and total current related in DC shunt field motor? --------- CORRECT ANSWER-----------------Inversely proportional What value isn't affected by speed changes in DC shunt field motor? --------
- CORRECT ANSWER-----------------Field current What are two types of speed control in DC shunt/series field motors? --------
- CORRECT ANSWER-----------------Armature control and shunt field control
Increasing resistance does what to speed? ---------CORRECT ANSWER---- -------------Decrease Which type of DC motor has higher resistance and many turns of fine wire? ---------CORRECT ANSWER-----------------Shunt motor Which type of DC motor has lower resistance and few turns of heavy wire? ---------CORRECT ANSWER-----------------Series motor Which DC motor has more high speed torque? ---------CORRECT ANSWER-----------------Shunt motor Which DC motor has higher start current/torque? ---------CORRECT ANSWER-----------------Series motor Which DC motor has higher low speed torque? ---------CORRECT ANSWER-----------------Series motor When is armature current max? ---------CORRECT ANSWER----------------- When motor is first turned on (RPM=0 CEMF=0) Is starter current greater or lesser than running current? ---------CORRECT ANSWER-----------------Greater than
What is a measure of velocity of rotating point ---------CORRECT ANSWER-----------------Runout How is runout rate (ROR) calculated? ---------CORRECT ANSWER----------- ------RPM X 2PIR (circumference) How is total runout distance calculated? ---------CORRECT ANSWER-------- ---------ROR X T Circular motion of point A will cause _____ motion of plate A --------- CORRECT ANSWER-----------------Linear Linear motion is equal to circular motion in terms of what? --------- CORRECT ANSWER-----------------Velocity, acceleration, distance Fixed RPM causes varying ROR and ROD depending on what? --------- CORRECT ANSWER-----------------Circumference In circular motion, V out is proportional to what? ---------CORRECT ANSWER-----------------Acceleration What are 3 popular motion sensors? ---------CORRECT ANSWER------------- ----Photo interrupter, photo reflector, magnetic pickup
What do position generators do? ---------CORRECT ANSWER----------------- cause a change in position, use electrical input to produce mechanical output What do position sensors do? ---------CORRECT ANSWER----------------- detect changes in position, use mechanical input to produce an electrical output What is a motor ---------CORRECT ANSWER-----------------a device that converts electrical energy into mechanical energy What is a generator ---------CORRECT ANSWER-----------------a device that converts mechanical energy into electrical energy What is an incremental motor ---------CORRECT ANSWER-----------------a motor whose shaft rotates a specific distance in degrees What is a continuous motor ---------CORRECT ANSWER-----------------one whose shaft continuously rotates without interruption when input is applied What type of generator produces DC volts and uses a commutator? --------- CORRECT ANSWER-----------------Dynamo
What are loads? ---------CORRECT ANSWER-----------------items that require motion and are driven by rotating shaft (motors) and electrical circuits that require power (generators) How are loads related to speed? ---------CORRECT ANSWER----------------- Inversely proportional What characteristic is the amount of work accomplished? --------- CORRECT ANSWER-----------------power How is power calculated in motors? ---------CORRECT ANSWER-------------- ---torque X RPM X K How is power measured? ---------CORRECT ANSWER-----------------Watts and HP How is power related to load and speed? ---------CORRECT ANSWER------- ----------Proportional to load and inversely proportional to speed When is torque greatest? ---------CORRECT ANSWER-----------------When RPM is 0 (locked motor) How much CEMF is generated in locked motor condition? --------- CORRECT ANSWER-----------------None
What is the definition of one horsepower? ---------CORRECT ANSWER------ -----------Power needed to lift 550 lbs 1 foot in one second or (33000 lbs in one minute) What principle of magnetism do motors operate on? ---------CORRECT ANSWER-----------------Attraction/repulsion What are basic parts of a motor? ---------CORRECT ANSWER----------------- Stator, armature (rotor), brushes, commutator, shaft Which position device rotates from one position to another according to digital/analog input? ---------CORRECT ANSWER-----------------Position generators Which position device receives mechanical input and produces analog/digital signal output? ---------CORRECT ANSWER----------------- Position sensor Define position ---------CORRECT ANSWER-----------------location of object, defined in 1, 2, or 3 dimensions in respect to reference Torque and RPM depend on the _____ of the shaft ---------CORRECT ANSWER-----------------Radius
Which digital position sensor would have 4 sensors? ---------CORRECT ANSWER-----------------Encoder wheel (gray or 8421) What type of encoder wheel produces incorrect outputs during transition? How is this overcome? ---------CORRECT ANSWER-----------------8421, overcome by strobe track or using Gray code In which speed controller does a low current control a high current motor? - --------CORRECT ANSWER-----------------Relay controller What are two types of starters? ---------CORRECT ANSWER----------------- Series and parallel A large start torque requires a _____ start current ---------CORRECT ANSWER-----------------Large What type of controller is used in small DC motors with small currents? ----- ----CORRECT ANSWER-----------------Solid state controllers (emitter follower) What type of start/speed controller uses D/A converter and comparator array? ---------CORRECT ANSWER-----------------Digital start/speed controller
What are two types of controllers used by DC motors? ---------CORRECT ANSWER-----------------Amplitude and Time control What are 3 types of AC motors? ---------CORRECT ANSWER----------------- Universal, induction, synchronous Which AC motor is used for large HP or special applications? --------- CORRECT ANSWER-----------------Synchronous Induction type AC motors use what kind of rotor? ---------CORRECT ANSWER-----------------Squirrel cage What induces current in the rotor (AC motor)? ---------CORRECT ANSWER-----------------expanding/contracting stator mag field What causes a magnetic field in rotor (AC motor)? ---------CORRECT ANSWER-----------------Rotor current induced by stator mag field How is slip speed calculated? ---------CORRECT ANSWER----------------- Field speed minus shaft speed What is field speed also known as (AC motors)? ---------CORRECT ANSWER-----------------Synchronous speed
What are two main parts of synchro? ---------CORRECT ANSWER------------ -----Stator and rotor How many stators does synchro use? ---------CORRECT ANSWER----------- ------3 windings in Y config What does TX stand for? ---------CORRECT ANSWER-----------------Torque transmitter What does TDX stand for? ---------CORRECT ANSWER----------------- Torque differential transmitter What does the torque receiver do? ---------CORRECT ANSWER--------------- --Electronically forced to reposition in response to applied voltage (from transmitter), provides mechanical motion What control component is similar to torque receiver? ---------CORRECT ANSWER-----------------Control transformer What are 4 steps of troubleshooting synchro systems? ---------CORRECT ANSWER-----------------Confirm symptom, remove power, isolate components, locate defect
What is a multimeter used to measure when troubleshooting synchros? ----- ----CORRECT ANSWER-----------------Ohms What fault will cause blown fuses or tripped circuit breaker? --------- CORRECT ANSWER-----------------Short rotor What fault causes transmitter to have little effect, receivers attempt to track, and low torque? ---------CORRECT ANSWER-----------------Open rotor An open in transmitter rotor will affect one device or whole system? --------- CORRECT ANSWER-----------------Whole system What fault causes all devices to point toward good stator axis? --------- CORRECT ANSWER-----------------Short stator A short stator in receiver will affect one device or whole system? --------- CORRECT ANSWER-----------------Whole system Define gyroscope? ---------CORRECT ANSWER-----------------mechanical device containing spinning mass that is universally mounted What gyroscope principle causes wheel to remain in fixed position if no force is applied? ---------CORRECT ANSWER-----------------Rigidity
