Motor Controls Level 3 Practice Test

These questions are part of the practice quiz. Start practicing

• In an SLC500 PLC system, the total number of modules and I/O points is limited to what can be installed in a single chassis.
• Feedback topology describes a path where the signal is returned to influence earlier stages. Which option best completes this statement?
• What device is installed on power lines feeding VFDs to lessen harmonics?
• A device that receives one type of energy and converts it to another type of energy and generally includes a sensor and a transmitter is called what?
• In a system diagram scenario, when evidence shows utility power is present at the emergency generator while there is a reported loss of power, which bracket indicates the new area requiring inspection?
• In the troubleshooting sequence, the first how many steps are repeated as often as necessary until the fault is located?
• During startup, most problems are identified and corrected in which area?
• Turbines and paddlewheels immersed directly in a process liquid are used to measure which quantity?
• Most DC motor contactors consist of how many sets of contacts?
• Which basic troubleshooting technique includes four levels of testing?
• Regenerative braking returns regenerated power of a DC motor back to the power source.
• The magnetic blowout coil produces a magnetic field between the breaking contacts that forces the arc up, increasing the length of the arc and causing it to dissipate faster. Which coil is this?
• Which statement about understanding operation is correct?
• What component do solid-state drives not use, resulting in energy not wasted as heat?
• Which type of PLC system manufactured by Allen Bradley allows multiple processors in the same chassis?
• When connecting an alarm light to the 02 terminals, the alarm would be powered how?
• Regenerative braking returns regenerated power to which of the following?
• Which trigger produces a deadband, preventing output switching ON and OFF as the input crosses the threshold?
• Which term describes focusing inspection on the most probable areas by progressively narrowing the search?
• The ? motor converts electronic digital pulses into mechanical rotational steps.
• What is a key benefit of avoiding premature tests during bracketing analysis?
• In a configuration that uses an external analog 0-10 VDC input, which connector is designated to receive that signal?
• Which type of manufacturing is described as the production of durable goods such as automobiles and refrigerators?
• The ? motor is a 3-phase motor in which the rotor turns at the same speed as the magnetic field of the stator.
• Which braking method decelerates the motor faster?
• When performing maintenance with the motor off, a visual inspection should include checks for excess dirt accumulation, burns, or damaged starter components.
• What parameter does a VFD vary to control the speed of an AC motor?
• What is the term used to identify the speed change in Segment 1 of a typical speed profile?
• What type of device has one type of analog signal as an input and produces another type of analog signal as an output?
• In motor stator temperature monitoring, thermocouples are faster to respond than RTDs.
• Which statement describes the devices used to provide speed reference signals in a closed-loop speed control system?
• Which type of network links multiple enterprise networks across broader geographic areas, often using public links?
• Which IEC programming language is commonly used to implement control diagrams in motor control applications?
• Which devices provide opto isolation between field device power and controller or motor drive system power?
• The motor connected to the VFD can be run in the reverse direction?
• Ramping works well for which loads?
• In a fixed and modular PLC, which interfaces provide the link between the PLC and external devices such as switches and sensors?
• Which load type is classified as constant torque loads?
• Which element of both PC and PLC architectures handles processing tasks?
• Which type of network media is capable of transferring data up to 100 Gbps?
• A 10-foot-tall tank uses a transducer that measures the liquid level with a 1-5 VDC signal monitoring the top 8 feet. If the transducer reads 3.5 VDC, how many feet of water are in the tank?
• What is the common term for a graphic terminal used to interact with an industrial network?
• Tachometer/generators and optical encoders are two types of devices generally used to provide speed reference signals in which speed control system?
• A motor control system that uses a tachometer to control the speed of the motor is called a(n) ? system.
• The physical path over which electrical or optical signals travel from one device to another is called the ?.
• The PC and PLC architectures share similarities such as a motherboard, memory, expansion slots, and which component?
• Where would you connect if converting to a closed-loop system by adding a 0-10 VDC analog source?
• Which materials are required for Type J thermocouples?
• The four listed circuit types AC/DC, DC current-sinking, DC current-sourcing, and TTL are the four most common types of which circuits used in controller input modules?
• Which type of servo motor is used for rapid positioning in industrial applications where low inertia is present?
• Which of the following is not an example of an analog signal?
• Which statement correctly pairs the type of signaling with its typical connection configuration?
• Which technique focuses on mapping the flow of power and information through a system?
• Which section of a DC drive is capable of controlling the motor direction?
• Is it important to understand and follow proper precautions and handling procedures to avoid ESD damage to solid-state devices?
• Open-loop motor control is characterized by which of the following?
• Motor driven proportional control valves are generally slower to operate than pneumatic control valves.
• In a 4-20 mA DC current loop, with a 250-ohm resistor connected in parallel to a 1-5 VDC relay, if the loop current is 12 mA, what is the relay input voltage?
• Proportional control valves are always controlled with an electronic voltage or current signal.
• The servo motor controller not only includes an amplifier that drives the servo motor, but also contains circuitry to receive sensor signals, control the system, and send signals to a PLC. True or False?
• How many factory default speeds are available for this VFD?
• What is the slip value for a synchronous motor at its operating speed?
• In most modern servo motor controls, what has replaced servo amplifiers as the controlling system?
• ControlNet is described as an open network standard, allowing any company to use it without licensing fees. This statement is true or false?
• TTL stands for Transistor-to-Transistor Logic. This term describes which category of components?
• Which displacement sensor is widely used for precise linear measurement and uses a transformer principle?
• Which IEC standard programming language most closely replicates traditional magnetic motor control diagrams?
• What term is used to describe a PLC where all essential sections are housed in one unit?
• Which troubleshooting technique uses external markers to identify the portion of the block diagram in which the fault exists?
• A tachometer/generator provides a feedback voltage that is directly proportional to which motor quantity?
• Which statement about field devices in relation to PLC hardware is true?
• If the emergency power generator is tested and shows no faults while loaded, what does this indicate about the generator?
• Troubleshooting techniques are proven procedures that provide a structure for the troubleshooting process.
• In a solid-state DC drive, the section capable of varying speed above and below the base speed is the
• Which statement about the blowout coil effects on arc behavior is accurate?
• Which PLC component is a printed circuit board that delivers power to the modules and provides the data bus for exchanging data between modules and the CPU?
• What is the primary purpose of line reactors in VFD-powered systems?
• Which network interconnects industrial devices such as limit switches, photoelectric sensors, valves, motor starters, process sensors, and operating interface devices via a single network?
• What term denotes the number of degrees the motor moves per step?
• Which statement best describes closed-loop control?
• In which PLC configuration are the processor, power supply, I/O modules, and communication modules all housed in a single unit?
• In modular PLC discrete outputs, which type provides mechanical contact switching?
• Which type of manufacturing produces consumables such as food, gas, paint, and chemicals?
• Which statement correctly characterizes a key difference between discrete control valves and proportional control valves?
• The Serial Real-time Communication System network uses which topology?
• Factory enclosures for VFD installations should have what rating appropriate to the level of protection for the installation?
• What term describes the maximum torque a stepper motor can withstand without moving when the stator is de-energized?
• Linear potentiometer position sensors sense the linear motion of an object.
• In a linear variable differential transformer, the secondary windings are connected in what arrangement?
• What is the temperature range a Type J thermocouple can sense?
• During dynamic braking, the motor operates as a DC generator after the main power is removed.
• Regenerative braking decelerates the motor faster than dynamic braking.
• Which coil in a DC contactor is specifically responsible for the arc blowout effect?
• Which term describes a device that takes an input analog signal and outputs an analog signal of potentially a different type or range?
• What is the voltage level of a Class 1 solid-state device that may cause potential damage?
• AC, DC, and TTL are the three most common types of which circuits used in controller output modules?
• In the tank description, what is the unmonitored portion of the tank height?
• What is the rapid flow of electrons between two bodies of unequal charge called?
• Convergent topology describes multiple inputs converging into a single path. Which option best completes this statement?
• The braking resistor in dynamic braking is connected to the armature leads.
• The SERCOS network uses which topology?
• If a normally open discrete contact is connected to turn the motor on and run forward, to which two terminals would you connect the contact?
• Which motor is typically used for precise open-loop positioning by stepping with digital pulses?
• Are all VFDs configured and programmed the same way?
• Which section of solid-state DC drives supplies the DC voltage to the motor?
• The VFD is an example of what type of control?
• In a servo system, which component within the controller is primarily responsible for driving the servo motor to the commanded position?
• Which two devices are used to monitor the speed of the motor for feedback in a DC drive?
• During the start of a DC motor using a rheostat, which statement about current is correct?
• With the same scenario but additional evidence that there is no outage to manufacturing or data equipment blocks, which bracket indicates the new area for testing?
• In PLC terminology, a stand-alone PLC is characterized by which of the following?
• To begin troubleshooting a VFD, four sections of a drive circuit must be inspected: input devices, output devices, programming configuration, and VFD internal components. Which option lists these four sections?
• What is the primary function of the backplane in PLC systems?
• DC currents stay above the zero axis and maintain a constant current flow to the motor. This describes currents that are which of the following?
• Before installing a VFD, the equipment manual and the labels on the VFD are two sources of information to consult. Which statement is true?
• Which statement best describes modular PLCs?
• Opto-isolators for AC signals contain how many LEDs, and DC circuits contain how many LEDs?
• PLC systems are used to control two classifications of industrial electrical systems. Which statement best describes them?
• A smart or intelligent device contains a solid-state circuit or chip that provides communication and diagnostic capabilities for the device.
• Which network type is used for process management including process variables, real-time process control, and diagnostics?
• True or False: A servo motor controller's described role includes receiving sensor signals, controlling the system, and sending signals to a PLC.
• All DeviceNet cable systems include device power and data integrated into a single cable system. Which network is this referring to?
• Which load type is classified as variable torque loads?
• Linear topology describes a signal path that travels through a sequence of stages with no branching. Which option best completes this statement?
• Ramp-up in a VFD-controlled motor refers to:
• Amortisseur windings in a synchronous motor help start by temporarily behaving like an induction motor before reaching synchronous speed.
• What term describes the maximum torque a stepper motor can withstand without moving when the stator is energized?
• Allen Bradley's SLC500 and CLX5000 are which type of PLC systems?
• Which list accurately identifies the four parts of a closed-loop motor control system?
• What type of flow meter requires particles in the fluid to reflect signals back to the flow sensor?
• External devices such as lamps, motor starters, and solenoids are examples of which PLC I/O category?
• A VFD operating without feedback from the motor is described as which control type?
• Generally, which type of signals with a very low source resistance are less sensitive to electrical noise from welders and electric motor starters?
• When using a VFD, a motor's ramp-up speed can be adjusted to vary from a few seconds to more than how many seconds?
• Which motor is driven to a commanded angular position using feedback control to achieve precise motion?
• Which type of servo motor is typically used in computer-related devices and CNC machines where starts and stops must occur quickly and accurately?
• What type of signal has only two states: ON and OFF?
• Which statement correctly describes how analog signals relate to a variable's value?
• Which network is primarily used for process automation and includes process variables, real-time control, and diagnostics?
• When a synchronous motor is connected to 3-phase power lines in parallel with other AC motors with lagging power factor, the synchronous motor will ? the power factor of the circuit.
• Which network is described as an open standard for industrial networking?
• Constant temperature and calorimetric sensors are types of which flow sensors?
• A smart device's self-diagnostic capability assists in what?
• Which type of signals provide a continuous indication of the value or position of the variable being monitored?
• Which network permits all nodes on the network to simultaneously access the same data from a single source?
• The speed of a DC motor is primarily controlled by adjusting which parameter?
• Which technique uses markers to isolate fault location within the diagram?
• Efficient troubleshooting of a network control system requires knowledge of the vendor's system software program.
• The motor that can be started manually with a rheostat is which type?
• A limit switch is an example of a discrete signal.
• 0-10 VDC, 4-20 mA, and 3-15 psi are examples of what type of signal?
• During operation of a DC rheostat motor starter, the resistance is increased in the field winding and reduced in the armature until the motor reaches full speed. Which option describes this change?
• Which device provides feedback voltage proportional to motor speed, used in speed control?
• Analog devices connected using a current loop analog signal are connected in what?
• What is the term for the connection of two or more thermocouples in series to increase output voltage?
• Which technique is described when brackets are widely separated and tests tend to be more general in nature?
• What does LVDT stand for?
• The statement 'It is important to make and break contacts as quickly as possible to extinguish the arc promptly and to extend the life of the contacts and contactor' is true. Which option best represents this assessment?
• Speed and ? are two physical quantities that must be controlled in a motor drive.
• PLC programming is performed by which device or tool?
• Which device is NOT listed as a programming device for configuring VFDs?
• Cable terminators are required on both ControlNet and DeviceNet networks to prevent reflections. This statement is true or false?
• A network consisting of intelligent machines connected together in a company building or group of company buildings is called a(n) ? network.
• How many steps are there in the troubleshooting sequence?
• Which programming software feature monitors and displays the value of all drive and motor parameters in real time?
• To monitor or program the VFD from a PC, which connector is used?
• Which topology involves two independent inputs merging into a single output?
• In which topology are network devices connected to a network media or cable, which is connected in a loop?
• Which modules in a control system are designed to have opto-isolation between field power and controller power?
• Block diagrams are used primarily to illustrate what?
• A signal can be used to control the speed of a motor, determine the position of a valve, or indicate the level of a tank as it fills. What type of signal is this?
• In which topology are all network devices connected to a central network media or cable identified as the backbone?
• The ? windings in a synchronous motor dampen speed fluctuations and allow the synchronous motor to operate as an induction motor until synchronous speed is achieved.
• What is the highest level of factory floor network architecture that provides an information layer for enterprise-wide data collection and program maintenance?
• Which formula relates current, resistance, and voltage in a simple resistor circuit?
• Devices such as switches and sensors, motor starters, pilot lights, and solenoid valves connected to a PLC are identified as which type of devices?
• Most new or upgraded DC systems use which starting method?
• Which statement about speed control in DC drives is true?
• The deadband in a trigger causes which of the following regarding output switching as the input moves around the threshold?
• The self-diagnostic capabilities of smart devices are helpful when troubleshooting smart systems.
• What type of flow meter depends upon the twist of the tube containing the flowing fluid to sense flow rate?
• Controller input and output modules have opto-isolation to prevent noise and operational problems. True or False?
• RTDs and thermistors are temperature sensing devices that exhibit a change in what, which is dependent upon temperature?
• Proportional control valves respond to an analog signal and adjust flow over which range of the valve’s capacity?
• In the tank measurement example, which voltage represents 8 feet of water?
• Which of the following is true regarding electrostatic discharge (ESD) in electronics handling?
• Which troubleshooting technique is a set of rectangles used to identify the parts of a system?
• Which type of analog signal can be used to not only control the speed of a motor, but also the direction of rotation of the motor?
• What type of signal is continuous, varying from a minimum to a maximum value?
• Re-torquing is a good procedure to use to check the status of terminals that are held in place with bolts or screws.
• PNP transistor output sensors are described as which type of current devices?
• Divergent topology describes a single input splitting into multiple outputs. Which option best completes this statement?
• Discrete control valves are binary; they have how many states?
• What is the term for a sensor output that sinks current from the load when active?
• In a modular PLC, which modules provide the link between the PLC and external devices that measure process conditions?
• DC drives use which method to smoothly accelerate and decelerate the motor?
• Which type of flow sensor uses a bluff body placed in the fluid flow to produce whirlpools or eddies?
• Which device is described as 'Device used to segment LANs to balance network traffic and to provide data filtering for security purposes'?
• Which statement best describes a switched path topology?
• When the core of an LVDT is at the center position, the output voltage is zero.
• When stopping heavy loads without a brake, what happens due to inertia?
• What term refers to the maximum number of steps the motor makes in one second?
• Which device is described as an electronic assembly that connects an individual device to the network?
• For long-distance analog control wiring, which signal type is preferable?
• Which type of motor is generally less expensive and requires less maintenance?
• For a stepper motor with an angular resolution of 1.8° per step, how many discrete steps are needed for a full 360° rotation?
• Which device documents industrial and commercial process data as analog output?
• A load cell is a sensor used to measure which physical quantity?
• Analog devices connected using a voltage type analog signal are connected in what?
• The ? motor is a position or motion correcting motor that is driven to a specific angular position as commanded by a control signal.
• How many DC motor wiring configurations are possible?
• In a fixed and modular PLC, which interfaces provide the link between the PLC and external devices such as lamps, motor starters, and solenoids?
• What DC control voltage is used to control the speed of the motor connected to the VFD?
• What is the speed in Segment 2 of the profile?
• Which of the following is NOT a standard DC contactor coil voltage rating?
• Arc suppression components are designed to absorb most of the interruption energy. Which option best describes this function?
• True or False: To better understand abnormal operation, it is essential to first understand normal operation.
• Which type of module connects to sensors that measure process conditions in a modular PLC?
• Based on the new information, where should the next test point be?
• What term describes a communication system where two or more intelligent machines share information?
• In a closed-loop speed control system, the set point speed value is the:
• Which network links branch offices and single mobile users to a local enterprise network or the Internet?
• The rating used to specify environmental protection for VFD enclosures is typically called what?
• The standard coil voltage ratings for DC contactors are 12, 24, 48, 120, and which value?
• Modular PLC discrete output modules are available with solid state AC, solid state DC, and ? type outputs.
• A network that acts as a data highway within an enterprise network is called a ? network.
• In a closed-loop control system, which term identifies the speed value that is compared with the actual speed to produce an error signal?
• Which signal flow topology could include linear, divergent, or convergent paths and contains switches that can change the flow of the signal?
• What type of connector is required to connect the communications cable to monitor or program the VFD with an external PC?
• In a closed-loop control architecture, which component is primarily responsible for comparing the requested speed with the actual speed and generating an error signal?
• The MicroLogix 1000 controller by Allen-Bradley is a stand-alone device and all I/O can be connected to its main chassis. Which option is true?
• The section that handles speed commands and logic in a DC drive is the
• During dynamic braking, the motor operates as which device after the main power is removed?
• Which troubleshooting technique is generally divided into two groups called power and information?
• For a stepper motor with an angular resolution of 0.72° per step, how many steps are required for a full 360° rotation?
• Arc chutes typically absorb greater than 80% of the energy released during the interruption of current flow as the contacts open. This is described as:
• Which device is typically immersed in a process liquid to measure flow?
• Three-phase motors typically have slip, which is the difference between rotor speed and field speed. What is the slip of a synchronous motor?
• TTL is an example of a logic family in digital electronics. What does TTL stand for?
• Which technique divides troubleshooting into two categories focusing on power paths and information paths?
• A PLC is an industrial what designed to control manufacturing machines and systems?
• In which topology are all network devices connected to a common device called a hub or switch?
• Modular PLCs are built by selecting components that fulfill the requirements for the control application and installing them into the rack or chassis. This statement is which of the following?
• Convert 88°C to Fahrenheit.
• NPN transistor output sensors are described as which type of current devices?
• RTDs and thermocouples are typical analog sensing devices that measure what in a process?
• In synchronous motors, ? have two winding types, salient pole windings and amortisseur windings.
• A typical hybrid stepper motor has how many rotor teeth?
• Which of the following can be used as programming devices to configure VFDs?
• What is the purpose of opto-isolation in controller modules?
• Which device is the central connecting device in a network, sometimes called a multiport repeater?
• For a stepper motor with an angular resolution of 90° per step, how many steps are required to complete a 360° rotation?
• Which section of a solid-state DC drive is capable of varying the motor speed above and below the motor base speed?
• What is the term used to identify the speed change in Segment 3?
• The LVDT output represents what physical quantity?
• Which device coordinates multiple servo axes by communicating with a PLC in a typical system?
• Rotary potentiometer position sensors detect the angular or rotational position of a shaft.
• To check if a rheostat is working properly, test each tap for a different resistor value using which instrument?
• Which statement is true about ultrasonic flow meters?
• At which step in a funneling analysis troubleshooting procedure are tests generally limited to a single unit in the system block diagram?
• Which statement best describes ramping in DC drives?
• True or False: By bracketing and funneling analysis procedures, pointless tests are avoided and wasted effort is eliminated.
• Most DC motor drives detect and display common circuit and/or fault numbers to help identify problem conditions.
• The control set points of a VFD establish the speed, rotation direction, and stopping parameters for the motor.
• Which statement is true about constant temperature and calorimetric sensors?
• Which PLC component provides the mechanical support for the modules?
• A bourdon tube pressure sensor often uses an LVDT to sense position relative to the applied pressure.
• Thermocouples are temperature-sensing devices that produce what type of signal when the temperature increases?
• Tachometer and encoder monitor which motor parameter?
• Which load type is classified as constant horsepower loads?
• Which of the following is an example of a field device connected to a PLC?
• SERCOS is an acronym for which phrase?
• Motor control systems that control motor speed without feedback data for torque or speed are called ? control systems.
• Lower initial cost and easier installation are two advantages of a(n) ? motor control system.
• Thermocouple transmitters generally produce 0-15 mA output signals.
• In an LVDT, the secondary windings are connected in series.
• In a field device powered sensor, which component provides optical isolation to prevent noise transfer?
• What are the three basic maintenance categories for a VFD?
• Stepper and servo motors are two special types of motors that require special input/output modules in a PLC system.
• A limit switch is an example of a(n) signal.
• Which type of pressure sensor uses a second process pressure as a reference instead of atmospheric pressure?
• In an LVDT, the primary winding is connected to what type of voltage?
• When troubleshooting a VFD, the four sections to inspect are input devices, output devices, programming configuration, and VFD internal components. Is this statement correct?
• A ? network connects enterprise networks together.
• The DC control voltage used to control speed is measured in which units?
• Transducers convert a variable such as temperature, position, flow, or pressure into what type of signal used by the control system?
• What is the full-scale voltage of the 1-5 VDC signal used to monitor the top 8 feet of water in the tank?
• Cable terminators are required on ControlNet and DeviceNet networks to prevent reflections. Which statement best describes this?
• What type of device converts from one analog signal range to a different analog signal range when the values don't match?
• When two or more thermocouples are connected in which arrangement to increase the output voltage from the sensor, the connection is referred to as a thermopile.
• A 1-5 VDC analog device can be used in a 4-20 mA DC loop circuit if a 250 ohm resistor is connected across the input to the device and the 4-20 mA DC current is routed through the resistor. The current signal produces the proper voltage to operate the 1-5 VDC device. (True/False)
• Which drive software feature displays drive parameters such as voltage, current, frequency, speed, and power consumed?
• A common type of sensor used to measure weight is a ____ sensor.
• Which topology is described by a signal splitting into two parallel paths after a single point?
• What is the effect of the blowout coil on the arc when a contact opens?
• Which network's acronym expands to Serial Real-time Communication System?
• A specification for an Ethernet network calls for a 100BaseT system. What type of cable is used for this network?
• The resistor value used to interface a 4-20 mA loop with a 1-5 VDC device is 250 ohms. Which option matches this value?