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questions and correct answers.
2025 NEIEP 400 Final review 78
questions and correct answers.
What material should be used for seating brushes? - ANSWER-Sandpaper
Readings on the meter appear to be inaccurate, what should you do? - ANSWER-Test meter
A machine that converts mechanical energy into electrical energy - ANSWER-Generator
What is the purpose of interpoles in a motor? - ANSWER-Helps prevent neutral planes from shifting
In the basic loop circuit generator armature supplies DC power to what DC elevator hoist motor component? - ANSWER-Motor Armature
If you have leakage resistance to ground, what will you use to test? - ANSWER-Megger
What kind of device would you use to measure current without disconnecting wiring? - ANSWER-Clamp on ammeter
What is the synchronous speed of 3 phase, 60 Hz, 6 pole motor? - ANSWER-1200 RPM
Before attempting to measure resistance in an unknown resistor in a circuit, what must be done? - ANSWER-Isolate from one side
What is the method used to resolve residual magnetism to an exitor? - ANSWER-Flashing the field
What is the inherent current limiter present for a rotating motor armature called? - ANSWER-CEMF
questions and correct answers.
In order to protect internal circuits, how is the 10 amp input jack on a digital multimeter usually protected? - ANSWER-Fused
What is the field protective relay in series with? - ANSWER-Motor shunt field
What material is used as insulation between the commutator and the armature shaft? - ANSWER-Mica
What elements make up commutator film? - ANSWER-Copper oxide film, graphite film, free graphite particles and waters vapor components
What does it mean when saturation occurs? - ANSWER-Holds all the magnetic lines of flux it can hold
What kind of meter would you use to detect a ground in the armature coils? - ANSWER-Ohmmeter
When should lubrication of motor bearings be done? - ANSWER-Not running
What would be the result if a meter set to current and connected to a voltage source? - ANSWER-Blow fuse
When commutation is good, what color is the commutator? - ANSWER-Chocolate
What is a precision shunt used for measuring? - ANSWER-Current
On a reversible D.C. door operator motor, what angle is the brush mounted? - ANSWER-Radially, straight up and down
What is the significance of the meter specification of ohms per volt? - ANSWER-Internal resistance at specific voltage
questions and correct answers.
What should resistance of a motor or generator commutator be to ground with the brushes raised? - ANSWER-Infinite Resistance
2230Ω can also be expressed as? - ANSWER-2.23 kΩ
Applied voltage on the primary leads current by? - ANSWER-90°
CEMF can best be described as? - ANSWER-Opposes applied voltage
Eddy currents can be described as? - ANSWER-Circulating currents set up by magnetic induction
a 1:12 fixed voltage transformation ratio transformer is? - ANSWER-Step-up
How would you check for an open primary winding? - ANSWER-Measure resistance across the primary
If the secondary winding is open what will happen to the secondary resistance? - ANSWER-It will be infinity
When the secondary winding is completely shorted what happens to primary current? - ANSWER- Current is high
How can you reduce ripple? - ANSWER-More coils and commutator segments
If current carrying wire is placed perpendicular to a field by two magnets of opposite polarity what happens? - ANSWER-Conductor is moved at right angles to the flux from the magnetic poles
Inherent current-limiter present for a rotating armature? - ANSWER-CEMF
Elementary AC generator has what that DC doesn't? - ANSWER-Split rings
questions and correct answers.
What provides the connection for the ends of the armature coils to the commutator? - ANSWER-Riser
Neutral plane is? - ANSWER-The point in a coils rotation where zero voltage is induced
Field that has only a few turns of heavy wire? - ANSWER-Series
Armature reaction can be compensated for by using? - ANSWER-Interpoole windings
What are two circuits of a separately-excited generator called? - ANSWER-The field and armature circuit
In a DC series generator current flows only when? - ANSWER-There is a load
An elevator that travels faster in the up direction when it is fully loaded that it does when it is empty is _________-compounded - ANSWER-Over
A shunt generators output drops as load is? - ANSWER-Increased
Generator series field is connected in parallel with? - ANSWER-Series field shunt
Series field Is connected is series with? - ANSWER-Armature
Final acceleration step for a hoist motor? - ANSWER-Weakening the shunt field
what type of generators pole pieces become excited by residual magnetism? - ANSWER-Self excited
Most common cause of commutator problems? - ANSWER-Brush pressure too light
questions and correct answers.
If your transformer read H1 to H2 = OL on you multimeter after isolating the transformer what would that indicate? - ANSWER-Primary winding is open
How is a sleeve bearing lubricated? - ANSWER-Oil carrier ring
When voltage change in a pole piece doesn't not produce a proportional change of magnetic flux, it is considered? - ANSWER-Hysteresis losses
Elevator is pulling through the brake after it stops at a floor. What is the likely problem? - ANSWER- Suicide circuit open
