QUESTIONS AND CORRECT DETAILED ANSWERS
(VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND
NEW!!
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
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
On the resistance scale of a digital meter, what does the lazy 8 symbol signify? -
ANSWER: Infinity
When some of the generator output is used to supply the field current how is the
generator described? - ANSWER: Self-exciting
When the multimeter is set to amps position the test leads are considered to be in
what state? - ANSWER: Short circuit
What should resistance of an armature be when measured from commutator to
ground with brushes removed? - ANSWER: High resistance
What method of armature winding is used for high current applications? - ANSWER:
lap winding
What should always be done to protect the meter from damage when measuring
unknown voltage? - ANSWER: Set to the highest range
To what scale should the ammeter be set in order to read a current of 2000 ma? -
ANSWER: 10 amp
What must be done when testing a resistance to avoid readings caused by parallel
circuit paths? - ANSWER: Remove one or two of the wire to the item being tested