BOMA Motor Controls Exam Questions and Answers All Correct
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Course
BOMA Motor Controls
Institution
BOMA Motor Controls
BOMA Motor Controls Exam Questions and Answers All Correct
The most practical switch used when the neutral connection must not be broken is a _____ switch? - Answer-Single throw
A _____ is used to measure electrical potential? - Answer-voltmeter
An ammeter is connected in series with the lo...
BOMA Motor Controls Exam Questions
and Answers All Correct
The most practical switch used when the neutral connection must not be broken is a
_____ switch? - Answer-Single throw
A _____ is used to measure electrical potential? - Answer-voltmeter
An ammeter is connected in series with the load? - Answer-True
When a conductor passes through a magnetic field, a current flow is always produced?
- Answer-True
A 4 S box is the most frequently used in one of the situations shown below. Which is it?
- Answer-Junction box
What is the material typically used in the manufacturing of metallic boxes used in
residential wiring? - Answer-Steel
Metering of utility company services to a building is usually done at? - Answer-The
service entrance point
A _____ is used to measure resistance? - Answer-ohmmeter
A _____ is used to measure current? - Answer-ampmeter
The difference between jogging and inching circuits is that? - Answer-Jogging circuits
remain energized for a specific amount of time, while inching circuits are energized only
until the inch button his released.
Most magnetic starters use double break contacts because the arc voltage is reduced to
half (1/2) its total value at each break. - Answer-True
The current rating of a contactor or starter is rated for? - Answer-Each individual contact
in the contactor or starter
Combination starters designed to have disconnect and the motor starter include in one
single enclosure? - Answer-True
,A starter that has 3 electrical separate sets of a power contacts would be classified as a
3 pole motor starter? - Answer-True
A set of normally open contacts are _____ when the relay is_____? - Answer-Open, de-
energized
A combination motor starter always includes? - Answer-Circuit breaker, fuse and
disconnecting device
The most difficult arcs to extinguish on a set of contacts are? - Answer-DC arcs
The symbol of normally closed contacts are two parallel vertical lines? - Answer-False
Replacing overload heaters or fuses on a three-phase circuit you should? - Answer-
Replace all three
Interrupting the circuit of one of the supply lines to a three-phase motor would? -
Answer-Make the motor single phase
The major cause of most motor failures is? - Answer-deterioration of the insulation
To indicate a good capacitor, the needle on an ohmmeter should? - Answer-Swing to 0
and slowly move to ¼, 1/3, ½ to way across the scale to infinity
Which of the following devices does not use a motor speed control? - Answer-Clocks
Rotary motion is produced by a motor. The twisting force causing the motion is called? -
Answer-Torque
Which of the following would not be the cause of excessive motor vibration or noise? -
Answer-Defective starter
The overload protection devices protect _____? - Answer-The motor windings
A device used to measure the rotating speed of the motor is called? - Answer-
tachometer
Generators make electricity by _____? - Answer-rotating armature in a magnetic field
A sudden current surge that occurs when a motor driven appliance is turned off is
_____? - Answer-Normal overcurrent.
In a transformer, the coil to which the induced voltage is applied is the _____? -
Answer-Primary
, The input voltage of a transformer is applied to a winding called the _____? - Answer-
Primary
A 3 way switch is essentially a _____? - Answer-Single pole double throw switch
If a switch can be closed by moving a contact to only one position, it is a _____ switch?
- Answer-Single throw
What is the purpose of grounding? - Answer-to insure safety
What is the abbreviation for heat resistant thermoplastic insulation? - Answer-THHN
Which type of overload device uses a bimetallic strip? - Answer-Thermal
What is a standard conductor? - Answer-Conductor composed of a group of wires
Thinwall conduit is another name for _____? - Answer-EMT
The result of connecting to large current load is _____? - Answer-Overload
A 3600 RPM motor has: - Answer-two poles
If you throttled the discharge side of a centrifugal pump into closed the amps would: -
Answer-go up
The common method of correcting power factor is: - Answer-add a capacitor
To convert AC to DC you would need: - Answer-rectifier
*To convert DC to AC we would need: - Answer-converter or inverter
The actual full load amps of a motor are found? - Answer-nameplate of the motor
Three factors which must be considered when selecting a fuse or circuit breaker: -
Answer-amps, volts, interrupting capacity
A fluorescent tube F40 has a diameter of: - Answer-1 1/2 inches
If the motor is drawing excessive amps you would expect to find it: - Answer-run hot
On a plan "scale 1/8" = 1', then 2 1/2 inches in a ruler equals: - Answer-20 feet
The most practical type of switch used to control lights from two locations is a _____? -
Answer-3 way switch
Electrical Metallic Tubing (EMT) is sometimes called: - Answer-thinwall
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