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WorksheetsFFA Ag Mechanics - Electrical Circuits and Motors
Total questions: 28
Worksheet time: 7hrs 0mins
An 1140 RPM motor fitted with a 7" diameter pulley drives a 4" diameter pulley at a speed of:
640 RPM
1530 RPM
1995 RPM
2280 RPM
A motor which can be run for over 60 minutes at a time is classified as:
Continuous duty
Intermittent duty
Hourly duty
Sporadic duty
Motor enclosures include drip-proof, splash-proof, and:
splash-resistant
dust-free
sealed
totally enclosed (explosion-proof)
Which electrical term on the electric motor nameplate identifies the cycles per second?
RPM
service factor
hertz
phase
Interchanging any two of the three energized wire leads to a motor is an appropriate way to reverse direction of rotation of a:
split-phase motor
capacitor-start motor
repulsion-start motor
three-phase motor
Which electric motor would have a wound rotor?
capacitor-start
split-phase
repulsion-start
shaded-pole
The push-button stations controlling the electric motor have "start" and "stop" switches.
The "stop" buttons are in parallel circuits.
The "start" buttons are in parallel circuits.
The connections alternate between stations.
Both A and B are correct.
A phase converter is a device that:
eliminates stray voltage
protects motors from overcurrent loads
allows three-phase motors to operate on single-phase current
adjusts the circuit power factor
The "SF" (service factor) indicates the:
Amount of overload the motor will take
rated horsepower of the motor
temperature rise the motor will take
maintenance requirements of the motor
Shaded-pole electric motors:
have high starting torque
are for difficult to start loads
would be good for use on a grain elevator
have low starting torque
The part of the AC electric motor that rotates is called the:
stator
frame
rotor
centrifugal switch
Which device can be used to sense the amount of moisture in the air coming from a grain dryer?
Pressure start
Float switch
Thermostat
Humidistat
To control a circuit carrying a large current by means of a low current circuit you should use a:
relay
SPST switch
DPST switch
SPDT switch
What would you attach to a limit switch to control the water level in an open tank?
Roller
Air vane
Float
Densitometer
What combination of switches may be used to control a light from four locations?
Four three-way switches
Two three-way and two four-way switches
Three 3-way and one 4-way switch
Four 4-way switches
Which of the following is a cable type that would be appropriate to use in a barn where the conditions will be moist?
NM (Dry/in wall)
GE
UF
(underground feeder)
TW
(Wire insulation type)
The major purpose of a ground-fault circuit interrupter is:
To protect equipment from damage due to overheating.
As a replacement for fuses in homes.
To protect humans from electrical shock due to a ground fault.
To protect appliances in case of a natural disaster.
When connecting the branch circuit wires within a panel board (circuit breaker box), it is common practice to place the white wire:
Under the lug of the circuit breaker.
To the terminal bar with the bare ground.
To the neutral terminal bar.
Under the lug of a fuse.
The purpose of a transformer is to change the amount of _______ from one value to another.
Watts
OHMS
Voltage
Microfarads
The NEC states that all current interrupting devices must be installed in the:
Undergrounded wire of the circuit.
Grounded wire of the circuit.
Neutral wire of the circuit.
Grounding wire of the circuit.
The brass-colored terminals of a receptacle represent the _______ terminals.
Neutral
White
Hot
Ground
What is the allowable number of conductors under each terminal screw?
1
2
3
4
When using a dimmer or on/off switch to control a low voltage fixture the device should be placed:
Output side of the transformer
Input side of the transformer
Either side is acceptable
Cannot be controlled by either one
Light bulbs in a low voltage circuit should be wired in:
Series
Parallel
Series and Parallel
On a (RFI) frequency
The largest fuse that can be used to safely protect 12 gauge wire is:
10 gauge
14 gauge
20 gauge
30 gauge
A fuse is always connected in:
Parallel with the load
series with the load
series-parallel with the load
either series or parallel depending upon circuit constants
Which side of a duplex receptacle outlet must be connected to the white wire?
The side with the small prong insert
the side with the large prong insert
the green screw
the housing box
The amount of continuous "overload" a motor can withstand at its rated Hz and voltage is indicated on the nameplate as:
Code
Hertz
Insulation Class
Service Factor
