Question

(might be 1 or 2, MCQ questions were having images given with them, which we couldn't insert, so ignore those questions if you cannot answer, sorry for inconveinience created, i tried to delete them but might be couldn't done all)

3) Single phase induction motors work because:
a) The oscillating magnetic field can
induce starting torque in a rotor.
b) The oscillating magnetic field can
induce running torque in a rotor.
c) A capacitance or inductance can create the phase shift needed to create a rotating magnetic field.
d) A, B, and C
e) B and C but not A
4) How can a capacitor start motor be identified?
a) The nameplate
b) A single cylindrical bump on the side of
the motor containing the capacitor
c) two cylindrical bumps on the side of the
motor containing the capacitors
d) A and B but not C
e) A and C but not B
5) How can a capacitor start / run motor be identified?
a) The nameplate
b) A single cylindrical bump on the side of
the motor containing the capacitor
c) two cylindrical bumps on the side of the
motor containing the capacitors
d) A and B but not C
e) A and C but not B
6) A single phase induction motor has a centrifugal switch and no capacitor. What type of motor is it?
a) A shaded pole motor
b) A split phase motor
c) A capacitor start induction motor
d) A capacitor run induction motor
e) A universal motor
7) What is the best choice of a single phase motor for a compressor?
a) A shaded pole motor
b) A split phase motor
c) A capacitor start induction motor
d) A capacitor run induction motor
e) A permanent split capacitor motor
8) If the centrifugal switch on a capacitor start motor fails, the motor will:
a) Run normally
b) Run normally, but draw more current
than usual
c) Not start
d) A, B, or C depending on the type of
failure
e) B or C depending on the type of failure
9) Single Phase motors may be reversed by:
a) Reversing the run winding, relative to the start winding
b) Reversing the start winding, relative to the run winding
c) Interchanging the connections to the power supply
d) A, B, and C
e) A or B but not C
10) Drum switches may be used to reverse:
a) 3 phase motors
b) Only single phase motors
c) Capacitor start induction motors
d) Any type of motor
e) Both three phase and capacitor start motors
11) A dual voltage single phase motor should be connected as follows:
a) T1, T3, and T8 together and T2, T4, and T5 together for low voltage
b) In series for low voltage and in parallel for high voltage
c) In parallel for low voltage and in series for high voltage
d) No changes are needed, voltage selection is automatic
e) According to the wiring diagram on the motor
12) A stepper motor is:
a) Designed for continuous rotation
b) Designed to move to and hold 4 discreet steps
c) Designed to move to and hold many discreet steps
13) For a given application:
a) Comparable stepper and servo motors will typically cost the same
b) A stepper motor will typically cost more than a comparable servo motor
c) A stepper motor will typically cost less than a comparable servo motor
d) A stepper motor will offer more control options
e) A and D
14) Stepper motors typically operate with:
a) A single phase
b) Three phases (X, Y and Z)
c) 4 phases
d) Two phases (A and B)
e) The number of phases varies with the motor design.
15) A 200 step stepper motor:
a) Has 200 poles
b) Has 100 poles on two phases
c) Has 4 poles on each of two phases
d) Is not commercially available
e) Is too complex to manufacture
16) When a stepper motor moves from one step to another:
a) The motor may overshoot
b) There is no possibility of overshoot
c) The overshoot will not exceed ½ step
d) A and C but not B
e) All of the above
17) Microstepping:
a) Reduces overshoot by smoothing the torque response of a motor.
b) Is achieved by varying the voltage applied to the two phases of the motor to achieve intermediate positions
c) Requires a motor with microscopic poles
d) A and B
e) A and C
18) An industrial servo motor system consists of:
a) A drive motor
b) A position encoder
c) A controller
d) B and C
e) A, B, and C
19) The motor in an industrial servo motor is typically:
a) A three phase induction motor
b) A DC motor
c) A single phase induction motor
d) A stepper motor
e) A shaded pole motor
20) The controller in an industrial servo motor system:
a) Is universal, any controller will work with any motor
b) Is always sold with the motor
c) Must be matched to the motor according to the manufacturer’s recommendation
d) A and B
e) B and C
21) Industrial servo motors may be controlled for:
a) Position
b) Velocity
c) Torque
d) A and B
e) A, B, and C
22) Industrial servo motors:
a) Are not capable of holding a fixed position
b) Have a holding torque that hold a fixed position with no movement
c) Hold a fixed position by making small corrections as the load moves, resulting in small oscillations
d) Are better than a stepper motor of holding a fixed position
e) Do not have enough torque that hold a fixed position with no movement
23) Limit switches can be used:
a) With stepper or servo systems
b) Can be used to prevent machine over travel
c) Can be used to automatically set the 0 point for a motor controller
d) B and C
e) A, B and C
24) In which of the following applications, would a servo motor not be appropriate:
a) Driving the X axis in a CNC mill
b) Driving the knuckle in an industrial robot
c) Driving a conveyor
d) Positioning a lens in a vision system
e) Driving a screw press
25) Stepper motors of the same faceplate size but longer length
a) Offer no difference in performance
b) Generally run at higher speed
c) Are generally capable of producing more torque
d) Generally run at lower speed
e) Generally run at longer period of time.
26) Servo motors generally operate at:
a) 24, 48 or 72v
b) 12, 18 or 36v
c) 100 or 200v
d) 200 or 400v
e) 120v
27) To increase the power of a stepper or servo motor without increasing the frame size:
a) This cannot be done, power is limited by frame size
b) A motor of a higher voltage may be specified
c) A motor can be operated above rated voltage to provide more power
d) A motor of a lower voltage may be specified
e) A motor can be operated below rated voltage to provide more power
28) For an intermittent load, such as a manual lathe, which method should be used to size the motor:
a) The motor’s nominal size should match the minimum load
b) The motor’s nominal size should match the RMS horsepower calculated based on the anticipated loads
c) The motor’s nominal size should match the maximum anticipated load
d) Any available motor can be used, the operator will adapt their work methods
29) In a conveyor the torque:
a) Is approximately constant regardless of speed
b) Increases linearly with speed
c) Increases exponentially with speed
d) Decreases linearly with speed
e) Decreases exponentially with speed
30) In a pump the torque:
a) Is approximately constant regardless of speed
b) Increases linearly with speed
c) Increases exponentially with speed
d) Decreases linearly with speed
e) Decreases exponentially with speed
31) A service factor of 1.25 allows a motor to:
a) Run at a speed 25% above rated
b) Supply a load 25% above rated for short periods of time
c) Supply a load 25% above rated for short periods of time under ideal operating conditions
d) Continuously supply a load 25% rate under any conditions
e) Continuously supply a load 25% rate under ideal operating conditions
32) Short cycling (starting and stopping a motor quickly multiple times in succession):
a) Will not harm a motor, they are designed to handle the high start-up currents
b) Should be avoided, excess heat will build up in the motor and damage the insulation
c) Should be avoided, the torque loading will damage the bearings
33) Increased motor temperature:
a) Has no impact on motor life so long as the maximum temperature is not exceeded
b) Can significantly decrease insulation lifespan
c) Has only a minor (at most 10%) impact on insulation lifespan
d) Has no impact on motor life so long as the full load amperage stays the same
e) Has no impact on motor life so long as the motor voltage is less the voltage specified on the nameplate
34) An open drip proof (ODP) motor enclosure:
a) Can operate with vertically dripping liquids
b) Has the internal components of the motor open to the environment
c) Is suitable for use in environments where explosive or combustible dust is present
d) A, B and C
e) A and B but not C
35) A totally enclosed fan cooled (TEFC)) motor enclosure:
a) Is cooled by circulating air over the exterior surfaces of the motor
b) Has the internal components of the motor open to the environment
c) Is suitable for use in environments where explosive or combustible gas is present
d) A, B and C
e) A and C but not B
36) An explosion proof motor (TEXP)
a) Is able to contain an internal gas explosion
6
b) Has the internal components of the motor open to the environment
c) Is suitable for use in environments where explosive or combustible gas is present
d) A, B and C
e) A and C but not B
37) A single phase motor is to be connected to a nominal 240 v single phase circuit. What would be the motor nameplate voltage?
a) 200 v
b) 220 v
c) 230 v
d) 240 v
e) 250 v
38) A three phase motor is to be connected to a nominal 600 v three phase circuit. What would be the motor nameplate voltage?
a) 460 v
b) 480 v
c) 550 v
d) 575 v
e) 600 v
39) A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the temperature to:
a) Increase
b) Decrease
c) Remain the same
40) A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the current to:
a) Increase
b) Decrease
c) Remain the same
41) A motor is running at 90% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the speed to:
a) Increase
b) Decrease
c) Remain the same
42) A motor is running at 110% of its nameplate voltage. Compared to running under the same condition at 100% of name plate voltage you expect the starting torque to:
a) Increase
b) Decrease
c) Remain the same
43) Motors with the same NEMA frame size are:
a) Electrically interchangeable (identical voltage and current ratings)
b) Mechanically interchangeable (same mounting hole locations and shaft size)
c) Mechanically interchangeable (same speed and horsepower rating)
d) Both electrically and mechanically interchangeable
e) The same colour
44) Which NEMA motor design type (sometimes called rotor type) is typically not used:
a) A
b) B
c) C
d) D
e) All types are in common use
45) Which NEMA motor design type (sometimes called rotor type) is typically used for industrial compressors:
a) A
b) B
c) C
d) D
e) The type does not matter
46) Which NEMA motor design type (sometimes called rotor type) is typically used for machine tools:
a) A
b) B
c) C
d) D
e) The type does not matter

47) Which is not a component of a DC motor:
a) Field Winding
b) Squirrel Cage Rotor
c) Armature winding
d) Brushes
e) Commutator
48) In a permanent magnet DC motor the
magnets take the place of the:
a) field Winding
b) Armature Winding
c) Bearings
49) A permanent magnet DC motor behaves
most like a:
a) Series excited motor
b) Separately excited motor
c) Compound excited motor
d) Universal motor

Answer 1