Semiconductor Basics
Electronics for Motor Control
Solid State Relay/MCC
Special Purpose Starters
Programmable Timers/Special Components
AC Motor Speed Control
100
The vertical line in the diode symbol (the striped end of the diode) denotes the _____.
A) anode
B) cathode
B) Cathode
100
A ___ has three leads identified as gate, main terminal 1, and main terminal 2.
A) BJT
B) JFET
C) Triac
C) Triac
100
The labels "A1 and "A2" are used to indicate the ___ on a ___ relay.
A) coil, IEC
B) coil, NEMA
C) contacts, IEC
D) contacts, NEMA
A) Coil, IEC
100
Smaller 3-phase motors are normally controlled using ___ across the line starters.
A) full voltage
B) reduced voltage
A) full voltage
100
Which type of timer maintains the timing value between input signals?
A) Asymmetrical
B) Non-retentive
C) One-shot
D) Retentive
D) Retentive
100
To operate a wound rotor motor at full speed, the rotor windings must be ____.
A) shunted
B) open
C) shorted together
C) shorted together
200
In an atom that has lost an electron, the place vacated by the free electron is referenced to as a _____.
A) hole
B) ion
C) proton
D) shell
A) Hole
200
____ devices are solid-state sensors, that detect the presence of a magnetic field.
A) Capacitive
B) Hall effect
C) Inductive
D) Ultrasonic
B) Hall effect
200
While a solid-state relay and an electromechanical relay perform the same function, the ___ relay has no moving parts as it switches electronically.
A) electromechanical
B) solid-state
B) solid-state
200
Reduced voltage starting is typically not used for ___ motors.
A) DC motors
B) single-phase AC motors
C) three-phase AC motors
D) wye-delta motors
B) Single-Phase AC Motors
200
Standard NO and NC symbols on a control diagram represent what type of contact function?
A) Instantaneous
B) Off-delay
C) On-delay
A) Instantaneous
200
In a wound rotor motor, resistors are placed in series with the ____ to control motor speed.
A) motor starter output leads
B) motor power leads
C) rotor windings
D) stator windings
C) rotor windings
300
When a diode is forward biased it's resistance is ____ and when it is reverse biased, it's resistance is ____.
A) high/high
B) high/low
C) low/high
D) low/low
C) low/high
300
When a transistor operates as a linear amplifier, it is operating in the ___ region.
A) active
B) cutoff
C) saturation
A) active
300
What device is used to protect solid-state relays from damage in a short circuit condition?
A) Metal-oxide varistor
B) Optical isolation
C) Resistor
D) Semiconductor fuse
D) Semiconductor fuse
300
Reduced voltage starting ___ inrush currents and ___ the impact on the distribution system.
A) increases/intensifies
B) lowers/lessens
B) lowers/lessens
300
Contact on a latching relay which prevent the coils from being continuously energized are called ___ contacts.
A) auxiliary
B) clearing
C) holding
D) sealing
B) clearing
300
Single-phase motor speed control circuits use SCR or ____ to control power to the motor for speed control.
A) diacs
B) diodes
C) triacs
C) triacs
400
Adding impurities to a pure material is known as the ___ process.
A) contamination
B) doping
C) impurification
D) rectification
B) Doping
400
A photoelectric sensor is set to signal a counter when a part passes between the transmitter and receiver blocking the light to receiver. This would be defined as the _____ operate mode of operation.
A) dark
B) light
C)sinking
D) sourcing
A) dark
400
MCC's with ___ units or buckets use a sliding track and mechanical lever.
A) fixed
B) removable
B) removable
400
The following drawing shows typical low-voltage starter configuration for a motor connected to a ___ - ____ starter.
wye-delta
400
___ latching relays use residual magnetic force to hold the contacts in position after the coil is de-energized.
A) Impulse
B) Magnetic
C) Mechanical
A) Magnetic
400
Which of the following solid-state devices would not normally be part of the power circuit in a single-phase AC motor speed control circuit
A) Diac
B) Silicon controlled rectifier
C) Transistor
D) Triac
C) Transistor
500
Two common semiconductor materials are _____.
A) aluminum & boron
B) iron & gallium
C) selenium & bismuth
D) silicon & germanium
D) Silicon & Germanium
500
Which of the following is not a common scanning method used by photoelectric sensors?
A) Diffuse scan
B) Direct scan
C) Inverted scan
Polarized scan
C) Inverted scan
500
The ____ should be used to install, operate, and maintain a motor control center.
A) manufacturer's manuals
B) NEC
C) project specifications
A) Manufacturer's manuals
500
Which type of reduced voltage starter is best suited for applications requiring long startup times, high torque, and low starting current?
A) Autotransformer starting
B) Part-winding starting
C) Primary resistor starting
D) Solid-state starters
A) Autotransformer starting
500
What type of voltage sensor could be used to monitor voltage in a system to insure that voltage remains between 203 VAC and 212 VAC
A) overvoltage sensor
B) undervoltage sensor
C) voltage band sensor
D) all of the above
C) voltage band sensor
500
Which section of a VFD conditions the pulsating DC output voltage waveform from the previous section, filtering and smoothing the waveform, to produce a pure DC waveform?
A) converter
B) DC bus
C) inverter
B) DC bus