Rotating Electric Machines LAP1: DC Series Motors
Which of the following is not a component of DC motor? A. Interpoles B. armature C. Bearing D. Commutator
Bearing (C)
Which of the following is a rule of safe dress around electric motors? A. Wear Safety Glasses B. Remove loose items C. Tie up long hair D.All of the above E. None of the above
All of the above (D)
The S.I. units of torque are_________ A.nanometers B.Kilometers C.Neutron-meters D. All of the above E. none of the above
none of the above (E)
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
run windings (A)
Which of the following statements is false about a separately- excited shunt motor? A. The shunt field is connected to a different power supply than the armature B. it allows you to vary the speed by varying the field current C. It requires only one power supply D. All of the above E. None of the above
It requires only one power supply (C)
Which if the following is an application of a DC series Motor? A. Loconotive B. Crane C.Hoist D. All of the above E. None of the above
None of the above
which of the following is a motor performance characteristic considered when selecting a motor for an application. A. torque output B.efficiency C. speed D. all of the above E. None of the above
All of the above (D)
The primary advantage of a SC Shunt motor is that it provides excellent _________ A. Starting torque B. Speed Control C. Efficiency D. Overheating Protection
Speed Control (B)
The amount of torque that a motor must generate at it shaft to drive the device it is driving is called the __________ A. opposing force B.Load C. Regulator D. all of the above E. none of the above
load (B)
If a motor is too heavy for you to move by yourself you should, ______ A. Get someone to help you move it B. Forget about it C. Take the rest of the day off D. move it anyway
Get someone to help you move it (A)
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
All of the Above (D)
Which if the following is an advantage of using a photo tachometer A. No direct contact with the motor shaft B. Less Expensive C. Quicker to use D. All of the above E. None of the above
No direct contact with the motor shaft
The relationship between the torque imput and the output of a gear drive depends on _________ A. the speed of the motor B. the size of the motor C. the direction of rotation D. all of the above E. none of the Above
None of the Above (E)
When two phases of electricity do not stat and end at the same time, they are said to be ____________ A. In-phase B. Inverted C. Repressed D. Out of phase
Out of phase (D)
Which of the following is a disadvantage of using an electric motor ? A. Short service life B. Can only produce rotart motion output C. Heating D.All of the above E. None of the above
heating (C)
The advantage of a series configured DC motor is that is can produce ______. A. constant speed B. high speed C. high starting torque D. variable speed
high starting torque (C)
The english unity of motor power are_____ A. kilowatts B. ft-lb C. horsepower D. volts
horsepower (C)
Torque is developed in an electric motor because of? A. gravity B. inertia C. interaction of different magnetic fields D. kinetic energy
interaction of different magnetic fields (C)
If a gear attached to a load has more teeth than the gear attached to the motor the speed of the load will be______ the speed of the motor A. more than B. Less than C. The same as D none of the above
less than (B)
The phases of the three-phase power supplies by the power company are__________ degrees out of phase with each other. A.60 B.90 C.100 D.120
120 (D)
The frequency of the AC electricity in most European countries is _________ A. 60Hz B. 75Hz C. 30Hz D. 50Hz
50Hz (D)
Which of the following is a method used to determine motor torque ? A. prony brake B. current measurments C. Dynamometer D. All of the above
All of the Above (D)
Which of the following is an application of a DC compound motor? A.conveyors B. Punch Press C. Bending machines D. All of the above E.None of the above
All of the Above (D)
In a belt drive system, the torque output delivered by the system depends on ___________ A. the diameter of the drive pulley B. the diameter of the driven pulley C. the torque output of the motor D. All of the above E. none of the above
All of the above (D)
Which if the following is an application for a DC Shunt motor? A. Centrifugal Pump B. Cooling Fan C. Woodworking machinery D. All of the above E. None of the above
All of the above (D)
Which if the following us an advantage of using an electric motor? A. Availability of electrical power B. Easily controlled with electrical controls C. Variety of types to choose from D.All of the above E. None of the above
All of the above (D)
Which of following is a wiring configuration for a DC Motor? A. Series B. Shunt C. Compound D. All of the above E. None of the above
All of the above (D)
Which of the following can be determined from a torque vs. Speed curve for a motor? A. Torque output B. starting torque C.speed regulation D. All of the above E. none of the Above
All of the above (D)
Which of the following is a category of electric motors? A. DC Motors B. Universal Motors C. AC Motors D.All of the above E. None of the above
All of the above (D)
Which of the following is an application of a slip-phase motor? A. Fan B. Centrifugal pump C. Business machine D. All of the above E. None of the above
All of the above (D)
The power that is supplied to a load by an AC power source is called _______ A. Reactive power B. Active power C. Apparent Power D. True Power
Apparent Power (C)
Which of the following statements is NOT true of A DC compound motor? A. It has a field connected in series with the armature B. it has a field connected in parallel with the armature C. Both fields are connected in parallel with the armature D. It has two configurations in which it can be connected
Both fields are connected in parallel with the armature (C)
The ____ provide a connection between the power source and the commutator on a DC motor A. armature B. Interpoles C. Brushes D. Field windings
Brushes (C)
The device that is used on a split-phase motor to disconnect the start winding when a predetermined speed has been reched is a ________ A. Limit switch B. Centripetal switch C.Pressure Switch D. Centrifugal switch
Centrifugal switch (D)
A _______ compound configuration is created by connecting the series and shunt windings so that their magnetic fields have the same magnetic polarity A. Differential B. self excited C. Cumulative D.Compound
Cumulative (C)
A quick test to determine if a motors torque demand is to high is to measure the motor_______ A. Current B. Voltage C. Resistance D. Inductance
Current (A)
Which of the following motors has the best speed regulation? A. DC series B. DC compound C. DC Shunt D. All of the above E. None of the above
DC shunt (C)
The amount two electrical waveforms are out of phase is measured in A. Volts B.Amps C. Degrees D. Seconds
Degrees (C)
The rate at which the electrical voltage or current cycle repeats is called__________ A. Frequency B. Randomized Rate C. Recurrence D.pulses
Frequency (A)
The Primary purpose of the interpoles is to.. A. increase motor speed B. Help reduce sparking between the commutator and the brushes C. make current flow in only one direction D. Provide a connection between the power source and the commutator
Help reduce sparking between the commutator and the brushes (B)
A DC Shunt motor has the field winding connected ____ with the armature A. In parallel B. In series C. In combination D. All of the Above E. None of the above
In parallel (A)
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
Is available at low cost (C)
The Primary advantage of a DC compound motor is __________ A. It provides a middle ground between a series and a shunt motor. B. It provides high starting torque C. It provides excellent speed control D. it is very efficient
It provides a middle ground between a series and a shunt motor. (A)
When a motor is ___________ the speed will decrease drastically from its rated speed. A. Oversized B. Unplugged C. Reversed D. Overloaded
Overloaded (D)
AC electricity flowing in a particular wire is called a _______ A. Phase B. Field C. Cycle D. Feed
Phase (a)
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
RMS- Root mean square
electric motors rely on the principle of _______ to convert electrical power into mechanical power A. Capacitance B. Inductance C. Resistance D. Gravity
Resistance (C)
Which of the following is not a method that can be used to revers the rotation of a split-phase motor? A. Revers the power leads B. Revers the start winding connections C.Reverse the run windings connections D. All of the above E. None of the above
Revers the power leads (A)
Which of the following procedures will not revers the direction of rotation on a DC motor? A. Reverse the field winding connections. B.Reverse the Armature Connections C. Reverse Power Supply Connections D. All of the above E. None of the above
Reverse power Supply Connections (C)
The rotational speed of a motor is measured in units of ___________ A. Resolutions per minute B. Turns per second C. Revolutions per minute D. All of the above E. None of the above
Revolutions per minute (C)
If a DC series motor is operated without a load, a condition called ______ will occur. A. Runaway B. Overdrive C. Hyper-speed D. Self-destruct
Runaway (A)
If the shunt field is connected to the same power supply as the armature , the motor is connection in the __________ configuration. A. Separately- excited B. Differential C. self- excited D. Compound
Self- Excited (C)
A DC ____ motor is one that has the field winding connected in series with the same armature A. Compound B. Series C. Shunt D. Servo
Series (B)
The waveform that is produced by alternating current looks like a _______ A. Sea wave B. sine Wave C. sawtooth wave D. square wave
Sine Wave (B)
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
Slip (B)
In which of the split-phase motor windings will the current start to flow first ? A. run windings B. start windings C. neither D. both
Start windings (B)
The ____ is the stationary winding of the electric motor. A. Stator B. Rotor C. Shaft D. Armature
Stator (A)
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
Synchronous speed (A)
instruments that are designed to measure motor speed are called _________ A. Speedometers B.Tachometers C.RPM meters D. dynamometers
Tachometers (B)
Active power is ________ A. the power used by a load B. the unused power returned to the source C. the power supplied but the power source D. All of the above E. None of the above
The power used by a load
Which of the following is a category of AC motors? A. Shunt Fed B. Compound wound C. Three-phase D.All of the above E. none of the above
Three-phase (C)
When a shunt field is connected to a different power supply than the armature it is called a(n) _________ shunt field A. compound B.differential C. separately- excited D. inverted
separately- excited(C)
The measure of a motor's ability to generate torque to move a load when the motor is just beginning to turn is called ________ A.Speed regulation B.starting torque C. Full-load torque D. counter torque
starting torque (B)
The amount of torque created is determined by the amount of force applied and ____________ A. the distance from the pivot point where force is applied B. the diameter of the object the force is applied to. C. the speed at which the force is applied. D. All of the above E. None of the above
the distance from the pivot point where force is applied (A)
