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WorksheetsElectric Motor 1
Total questions: 48
Worksheet time: 24mins
The waveform that is produced by altering current looks like a _____
A) Sea wave
B) Sine wave
C) Sawtooth wave
D) Square wave
The frequency of the AC electricity in most European countries is _____
A) 60 Hz
B) 75 Hz
C) 30 Hz
D) 50 Hz
The rate at which the electrical voltage or current cycle repeats is called _____
A) Frequency
B) Randomized rate
C) Recurrence
D) Pulses
The effective value of AC voltage is also called the _____ voltage
A) FMS (Frequency Modulated Sinewave)
B) EMS (Electrical Modified Source)
C) RMS (Root Mean Square)
D) All of the above
E) None of the above
AC electricity flowing in a particular wire is called a _____
A) Phase
B) Field
C) Cycle
D) Feed
The amount two electrical waveforms are out of phase is measured in _____
A) Volts
B) Amps
C) Degrees
D) Seconds
The phases of the three-phase power supplied by the power company are _____ degrees out of phase with each other
A) 60
B) 90
C) 100
D) 120
When two phases of electricity do not start and end at the same time, they are said to be
A) In-phase
B) Inverted
C) Repressed
D) Out of phase
Which of the following is a category of AC moters
A) Shunt fed
B) Compound wound
C) Three-phase
D) All of the above
E) None of the above
Which of the following is a type of single-phase AC motor
A) Capacitor-start
B) Permanent-capacitor
C) Split-phase
D) All of the above
In which of the split-phase motor windings will be the current strt to flow first
A) Run windings
B) Start windings
C) Neither
D) Both
The device that is used on a split-phase motor to disconnect the start winding when a predetermined speed has been reached is a _____
A) Limit switch
B) Centripetal switch
C) Pressure switch
D) Centrifugal switch
The main set of windings in a split-phase motor is called the _____
A) Run windings
B) Start windings
C) Primary windings
D) Secondary windings
Which of the following is an advantage of a split-phase motor
A) Produces high starting torque
B) Produces low starting torque
C) Is available at a low cost
D) All of the above
E) None of the above
The speed at which the rotor/shaft of an AC motor must rotate to exactly match the speed of the rotating magnetic field is called _____
A) Synchronous speed
B) Slip speed
C) Overdrive speed
D) All of the above
E) None of the above
The difference between the synchronous speed and the actual speed at which an AC motor will run is called _____
A) Slop
B) Slip
C) Differential
D) All of the above
E) None of the above
Which of the following is an application of a split-phase motor
A) Fan
B) Centrifugal Pump
C) Business Machine
D) All of the above
E) None of the above
Which of the following is not a method that can be used to reverse the rotation of a split-phase motor
A) Reverse the power leads
B) Reverse the start windings connections
C) Reverse the start run windings connections
D) All of the above
E) None of the above
What does an AC power source supply
A) Reactive power
B) Active power
C) Apparent power
D) True power
E) All of the above
The cost of electrical power is based on _____
A) The cost of the wire used to transmit the power
B) The amount of loads connected to the power lines
C) The amount of reactive power
D) The amount of power supplied
The ratio of active power to the apparent power in an AC circuit is called the _____
A) Power rating
B) Power factor
C) Demand power
D) All of the above
E) None of the above
The power factor of 100% IS called _____
A) Unity power factor
B) Absolute power factor
C) Leading power factor
D) All of the above
E) None of he above
Poer factor correction capacitors are rated in _____
A) Farads
B) Ohms
C) Volt-amperes-reactive (VAR)
D) Amps
A capacitor start motor produces more starting torque than a split phase motor because the capacitor creates a larger _____ shift between winding currents
A) Voltage
B) Reactance
C) Phase
D) Reluctance
A disadvantage of the capacitor-start motor is _____
A) Increased cost
B) Decreased starting torque
C) Increased phase shift
D) Decreased capacity
Which of the following is an application for a capacitor-start motor
A) Power tools
B) Pump
C) Small machines
D) All of the above
E) None of the above
Most commonly, a bleeder resistor is
A) 12 kilo-ohms
B) 20 kilo-ohms
C) 15 kilo-ohms
D) All fo the above
D) None of the above
The fourth color on a resistor represents _____
A) The multipler
B) The division factor
C) The second digit of the resistance valve
D) The tolerance of the resistance valve
Which of the following is not a component of a permanent-capacitor
A) Start windinv
B) Run winding
C) Capacitor
D) Centrifugal switch
Which of the following is a disadvantage of a permanent-capacitor
A) Low starting torque
B) Not easily reversible
C) Motor vibration
D) All of the above
E) None of the above
Which of the following is an advantage of a permanent-capacitor motor
A) Higher efficiency
B) Quieter running
C) Lower maintenance
D) All of the above
E) None of the above
Which of the following is an application of a permanent-capacitor motor
A) Fan
B) Lathe
C) Blower
D) All of the above
E) Both A and C
Which of the following is not a method used to adjust the speed of a permanent-capacitor motor on a multispeed fan
A) Different resistors in series with the motor windings
B) Adding capacitors in parallel with the motor windings
C) Use an autotransformer to step down voltage
D) All of the above
E) None of the above
A capacitor-start capacitor-run motor is basically a combination of a capacitor-start and a _____
A) Three-phase motor
B) Permanent-capacitor motor
C) Split-phase motor
D) Compound motor
Which of the following is an advantage of a capacitor-start capacitor-run motor
A) Quiet running
B) High running torque
C) High starting torque
D) All of the above
E) None of the above
Which motor is the most commonly used capacitor motor
A) Permanent-capacitor
B) Capacitor-start motor
C) Capacitor-start capacitor-run motor
D) All of the above
E) None of the above
Which of the following is a category of three-phase AC motors
A) Induction motor
B) Synchronous motor
C) Compound motor
D) Both A and B
E) None of the above
About _____ of the AC motors used in industry and induction motors
A) .15
B) .95
C) .8
D) .5
The average rang of slip for a squirrel-cage induction motor is _____
A) 5-10%
B) 8-12%
C) 2-6%
D) 15-18%
The squirrel-cage motor gets its name from the design of it _____
A) Rotor
B) Frame
C) Stator
D) Shaft
The three phases that are fed to the stator windings of a three-phase motor are _____ degrees apart
A) 90
B) 75
C) 60
D) 120
Which of the following is an advantage of a three-phase induction motor
A) Higher efficiency
B) High power factor
C) Excellent speed regulation
D) All of the above
E) None of the above
Which of the following is an application of a three-phase induction motor
A) Large conveyor systems
B) Machine tools
C) Large pumps
D) All of the above
E) None of the above
In a wye, 4-wire circuit _____ is the return path for each phase
A) L1
B) L2
C) Neutral
D) L3
Which of the following is a wiring configuration for a three-phase induction motor
A) Wye
B) Split-phase
C) Delta
D) Both A and C
E) None of the above
If the winding halves on a wye dual-voltage three-phase motor are connected in series, the motor is connected for _____ operation
A) Low voltage
B) Reverse
C) Reduced voltage starting
D) High voltage
Connecting the winding halves of a delta motor in parallel connected the motor for _____ operation
A) Low voltage
B) Reverse
C) Reduced voltage starting
D) High voltage
Switching lines _____ will reverse the direction of a three phase motor
A) L1 and L2
B) L2 and L3
C) L3 and L1
D) Any of the above
