Independent Electrical Contractors (IEC) Year 2 Part 3 Practice Test

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• What are the line-to-line voltages in a 3Ø, 4-W supply system delivering 120/208 volts?
• What types of output voltage configurations can many three-phase generators deliver?
• How can transformer power losses be minimized?
• A 5 KVA transformer rated for a primary voltage of 480 volts can deliver a maximum output of how many kVA if the applied voltage is 440 volts?
• For a 90 KVA, 240-volt motor, how much current will each circuit conductor carry?
• What natural phenomenon can be caused by two like-charged objects?
• Which of the following is a requirement for a transformer to function effectively?
• Which of the following is NOT true regarding three-phase systems?
• What does a dry-type transformer use for dissipating excess heat produced by the windings?
• What happens to the strength of the magnetic field when the current flow through a conductor increases?
• A lockout can be removed by ___.
• What letter represents impedance in electrical circuits?
• What are the principal causes of accidents on construction sites?
• What is an electric device that uses electromagnetism to change voltage from one level to another?
• A transformer has a 120/208-volt wye secondary and is delivering 75 amps of line current to a 3Ø load. For safety, this transformer must be rated for at least how many KVA?
• Which type of motors are permanent magnets used in the construction of?
• How does an increase in the primary voltage affect the secondary output of a transformer with a fixed turns ratio?
• What happens to the efficiency of a transformer when the temperature rises excessively?
• Each employee at the edge of what depth excavation must be protected from falling?
• If the higher voltage of a slash-rated three-phase voltage system equals twice the lower voltage, how is the system configured?
• In terms of transformer power output, what does kVA measure?
• If a control panel is connected with the correct input voltage and transformer type, which voltage should be observed at the output?
• What is the typical effect of an increased inductive reactance in an AC circuit?
• The relationship between true power and apparent power defines which electrical concept?
• What type of fall protection is described by using covers over openings?
• Where are loads typically connected on a transformer?
• Which connection diagram is appropriate for a 2-pole breaker 120/240-volt panelboard supplying a load designed for 12 volts?
• What is the current-limiting characteristic of a transformer?
• What does reactive power describe in an electrical circuit?
• What type of current does a non-linear load produce?
• What type of wire is used for the load drawing 19.8 amps at 208 volts?
• For a load drawing 27.8 amps in a 120/240-volt three-phase panel, what is its power usage in kVA?
• The unit of measurement for power is ___.
• For a 19.8-amp, 3Ø, 208-volt load 152 feet from the panel, what is the smallest circuit conductor you can use to limit voltage drop to 1.8%?
• Lockout/Tagout devices should be substantial, durable, and ___.
• What can buck-boost transformers deliver secondary voltages rated at?
• Impedance in electrical engineering is measured in which units?
• Can buck-boost transformers be used for voltage drop correction with varying loads?
• Why is a broad knowledge of soils and soil types necessary in excavation work?
• As two magnetic poles of the same polarity move closer together, the force of what becomes stronger?
• What is the minimum height that requires protection from falling in a hoist area?
• What line-to-neutral output voltage is available from a 480 primary to 120/240-volt secondary transformer without tap changes?
• What is the voltage between C phase and ground in a 240-volt corner-grounded delta?
• In an inductive circuit, how does the current behave in relation to the applied voltage?
• Besides resistance, which components influence current flow in a circuit?
• Which requirement is crucial for operating buck-boost transformers effectively?
• The sum of resistance, inductive reactance, and capacitive reactance in a circuit is known as what?
• On a transformer's nameplate, how is the rated power output expressed?
• What determines the amount of load a transformer can supply to 120-volt equipment?
• Are dry-type transformers filled with oil to reduce overheating?
• What is the maximum amp delivery of a 25 KVA transformer with 120/240 volts secondary windings when connected to a 240-volt load?
• The opposition to the flow of alternating current is influenced by which of the following factors?
• What term describes the combination of true power and reactive power in an AC circuit?
• What does electrical current represent in a circuit?
• Three-phase, four-wire systems can provide power to which types of loads?
• When a 3Ø, 3-W supply system delivers 240 volts, how is the system connected?
• What is the significance of K-value in electrical circuits?
• Where the circuit voltage is 240 volts, can a "Buck-Boost" transformer be utilized to operate a load rated at 12 volts?
• What types of excavations require fall protection for employees if they are 6 feet or more in depth?
• Transformers are normally rated in VA, which indicates what?
• What measurement is required to determine the output current of a transformer?
• To power 120-volt loads only, how should the two secondary windings be connected?
• In alternating current (AC) circuits, what is the nature of the reactance?
• Which of the following is measured in ohms?
• If 120-volt loads are required to be connected to a delta transformer, what must be implemented to provide two 120-volt outputs?
• Inductive reactance is measured in which unit?
• A transformer is capable of changing which of the following?
• What type of transformer is used to produce an output of 12 volts from a 120 x 240-volt primary?
• Which electrical component introduces a phase shift in current below zero degrees?
• Which conductor in a delta transformer is associated with safety and electrical grounding?
• Which coil of a transformer is to which the supply voltage is connected?
• In a 120/208-volt 3Ø, 4W panelboard, how many more amps of load could you add to AØ before overloading a 45 KVA transformer?
• If the phase angle of a circuit is 28 degrees, the power factor is approximately ___%.
• What is the capacitive reactance in ohms for a 60 Hz circuit containing a 12 µF capacitor after converting microfarads to farads?
• What occurs when the supply voltage differs from the nameplate rated primary voltage of a transformer?
• OSHA standards apply to which of the following?
• Which materials are not attracted by the magnetic field around a magnet?
• What type of transformer is used for sensitive electronic equipment to help "clean up" the power?
• When AC current flows through a circuit conductor, what is created that opposes the applied voltage?
• In a large service installation, what type of transformers are contained within CT cans?
• If a hazardous liquid is spilled, what is the proper procedure?
• Which symbol is used to represent a capacitor in a schematic circuit?
• What characterizes a bolted fault?
• Why is it essential to include interrupting ratings for OCP devices on the secondary side of transformers?
• What is the output of an AC generator measured in cycles per second called?
• Who has control of unsafe acts on construction sites?
• What is the current carried by each circuit conductor connected to Circuit LB-6,8?
• In a step-down transformer, how does the secondary voltage compare to the primary voltage?
• When two like-charged bodies are brought together, their fields will work to do what?
• When connected to boost the input voltage, how are primary and secondary voltages affected?
• Lockout/Tagout devices should be ___.
• Which of the following is NOT a contribution of circuit conductors?
• A transformer is measured at 1.2% impedance; what does this primarily affect during a fault condition?
• What is the minimum interrupting rating required for an OCP on the secondary of a 150 KVA transformer with a 2.07% impedance?
• What is a potential downside of operating a transformer beyond its nameplate ratings?
• When using a transformer, what is transferred from the primary to the secondary?
• What feature do large dry-type distribution transformer enclosures have for facilitating airflow?
• If the coils of a buck-boost transformer are connected in parallel, what is true about the voltages?
• What is an example of unsafe conditions on a construction site?
• In a transformer, what happens when an open circuit occurs in the secondary winding?
• In a scenario with all loads operating, what is the current flowing through BØ in the main breaker?
• Which type of transformer bank is indicated when the secondary voltage is 240 volts?
• In a 120/240-volt, 3Ø, 4-W open-delta bank of transformers, what does the line current equal?
• What phenomenon is created around a conductor when current flows through it?
• The unit of measure for capacitance is ___.
• What determines the maximum output power of a transformer?
• What do the terms insulating transformer and isolating transformer refer to?
• What is the allowable maximum current in amps from a .5 KVA transformer operating at 12 volts without being overloaded?
• Regardless of who created an unsafe condition, what should you do?
• What happens to total current in a parallel circuit if the resistance decreases?
• What must be used when working in excavations that are not made in stable rock?
• Which component is installed on dry-type distribution transformers to make them weather resistant for outdoor installations?
• Which of the following represents typical high transmission voltages?
• What is the relationship between unsafe acts and safe working conditions?
• If the input voltage is 208 volts, what voltage will be applied to a control panel that requires 230 volts?
• The magnetic field strength around a conductor is at its maximum when the AC current is at which degree?
• What is the purpose of identifying the exact location of underground utilities before excavating?
• OSHA's Lockout/Tagout standards outline required measures for controlling hazardous ___ energies.
• What is the required voltage for a 1Ø motor that draws 25 amps in a 240 x 480 - 24/48-V transformer?
• In a 3Ø, 4-W supply system delivering 120/208 volts, what is the line-to-line voltage?
• To deliver 1 kVA of power with a transformer operating at 95% efficiency, how much power in VA is required from the primary?
• When must a transformer be derated?
• What aspect does OSHA standard 1926.451 specifically cover?
• A capacitor discharges most rapidly when it is connected to which type of circuit?
• What is one way to prevent unsafe acts on construction sites?
• What connection type would allow a transformer's secondary windings rated 120/240 to deliver 240 volts?
• When power is applied to the primary of a transformer, what does it induce in the secondary?
• In a single-phase transformer with a dual-voltage secondary, the total power rating is the sum of what?
• The total current in a parallel circuit supplied from a 2-pole breaker is calculated to be what value, given a resistance of 25 ohms and reactance components?
• If a wye-connected transformer has a line-to-line voltage of 208 volts, what is the voltage across each winding?
• What is the total kVA of three-phase loads drawing 16, 42, and 75 amps from a 240-volt panel?
• If a transformer feeding a 120/208-volt panel has a Z of 2.2%, what is the bolted short-circuit fault current available on the secondary?
• For which type of load is a Buck-Boost transformer primarily designed?
• What action should you take in the event of a hazardous material spill?
• When designing circuits, understanding reactance is important for which reason?
• Are a transformer's primary winding and secondary winding connected together?
• What does the OSHA standard for Fall Protection specifically address?
• Which of the following is an example of a non-linear load?
• Do PCBs contained in oil contribute to airborne health hazards?
• When a 120/208-volt, 3Ø, 4-W supply system delivers power to a load, what does the line voltage equal?
• A three-phase 69 kVA load connected to a 120/240-volt three-phase panel will draw how many amps through each conductor?
• What protective measures are required when working over dangerous equipment?
• When inductors are in series, they add like which other electrical component?
• True power in an electrical circuit is primarily used by which type of load?
• What happens to current and voltage in a purely resistive circuit?
• What is the maximum phase angle between current and voltage in purely inductive or purely capacitive circuits?
• What type of transformer is being described with a 100 KVA rating and a 1.8% impedance designed for a 240-volt panel?
• Which statement is true regarding the capacity of a hoist?
• Which combination reflects the correct types of crane accidents involving tipovers and electric lines?
• How many coils (or windings) does an isolation transformer consist of at a minimum?
• As current flow through a conductor creates a magnetic field, what can be said to happen with consistent current flow?
• Which type of transformer connection is used when dealing with supply-circuit voltages of 206 volts for equipment rated at 220 volts?
• If a transformer has a short-circuit current rating of 115,655 amps, what type of scenario would likely lead to this amount of current?
• What type of transformer bank is described if it is a delta-connected bank?
• What is the impedance in a circuit with a resistance of 10 ohms and an inductive reactance of 15 ohms?
• Substations are primarily used to do what?
• What is the term for placing your body or body parts into dangerous moving parts of machines?
• What is the smallest calculated size transformer that can supply a panel with 80 amps per phase load and multiple 3-phase loads?
• Which type of connections are more common for transformer primaries?
• A transformer with a nameplate reading of 130-volt primary - 16-volt secondary, if 110 volts is applied, what output voltage can it supply?
• A 1-phase transformer supplying 332 amps to a 240-volt load delivers how many KVA to the load?
• Which types of transformers are utilized for neon lighting and long-distance transmission?
• In a circuit with 25 ohms resistance and 50 ohms capacitive reactance, what is the calculated impedance?
• In a delta-connected transformer, what is the relationship between line and phase voltage?
• When a buck-boost transformer is used to buck the input voltage, how are the primary and secondary voltages related?
• Can a "Buck-Boost" transformer be used to operate a 240-volt rated load on a 208-volt supply voltage?
• Which of the following statements is true of delta-configured voltage systems?
• What happens to a transformer's lifespan when it operates in too high an ambient temperature?
• What is one significant use of PCBs in electrical applications?
• Which transformer type has windings that share a common part?
• What is the monthly energy cost to operate an 85-watt PAR38 incandescent lamp when electricity costs $0.13 per kW-hr and the lamp is used for 13 hours a day?
• Which type of circuit will show a phase difference between current and voltage?
• Which scenario occurs when current flows in a conductor?
• Compliance with Lockout/Tagout prevents an estimated ___ fatalities each year.
• What rank do falls hold as a cause of construction deaths?
• What are the line-to-line voltages when a 3Ø, 4-W supply system delivers 120/240 volts?
• The drawing that represents a sine wave to an electrician illustrates what concept?
• The turns ratio of a transformer can be expressed in which way?
• How many amps will a 208-volt, 17.2 KVA single-phase load draw at a 120/208-volt three-phase panel?
• What is the impedance of a series circuit composed of resistance and reactance values of 25 ohms, 14 ohms, and 10 ohms?
• Can a buck-boost transformer be used at a circuit voltage of 208 volts for a load rated at 240 volts?
• Who is responsible for determining if a walking/working surface has the strength to support employees safely?
• Inductive reactance is primarily related to which of the following?
• Which letter represents impedance in electrical circuits?
• What type of energy conversion occurs in an inductor when current changes?
• What is the voltage between B phase and ground in a 240-volt ungrounded delta?
• What current does a 3Ø, 480-volt, 45 kVA load draw compared to a delta-connected load?
• A 1Ø transformer rated at 500 VA can deliver how many amps to a 120-volt load without overheating?
• If a transformer "hums" after it is energized, what does it indicate?
• What is the secondary current in amps if a 120-volt primary transformer has a primary current of 2 amps?
• Reactive power is measured in what unit?
• If the RMS value is 125 volts, what is the peak value?
• What is a potential hazard of operating a crane?
• What is the requirement when working at heights to reduce fall hazards according to OSHA?
• What is the relationship between flow and current flow in electrical circuits?
• What is the power used by a 12-volt circuit with 24 amperes of current?
• According to OSHA's general duty clause, which employer responsibility is mandated?
• Which protection systems can be used for employees on elevated surfaces with an unprotected side or edge?
• The Powered Industrial Trucks standard includes which of the following?
• What unit measures electrical inductance?
• What is eddy current loss in a transformer?
• In a 3Ø, 4-W supply system delivering 277/480 volts, what are the line-to-neutral voltages?
• What symbol is commonly used in a schematic circuit to represent an AC power source?
• A coil of wire carrying current behaves like what?
• What is an open delta?
• Which of the formulas is correct to find the equivalent of 3 inductors in a series circuit?
• The invisible magnetic lines that leave the north pole and enter the south pole are called what?
• A Group III B-B transformer has a turns ratio of what?
• Using a 120/240V-12/24V Group I transformer, what voltage is supplied to equipment rated for 220 volts when the supply-circuit voltage is 206 volts and Diagram 4 is used?
• Is the winding current in Coil 1 equal to the current in Heating Element A?
• The power factor for a load is ___% if true power equals 11 kW and apparent power equals 12 kVA.
• What voltage adjustment can be made using taps on a transformer?
• Which secondary transformer connection is used to supply the correct voltage for a 240-volt load?
• Which electrical component is primarily used to store energy in an electric field?
• What term describes the opposition to current flow in an AC circuit with resistance and inductance?
• If a three-phase load draws 37.3 amps at 208 volts, what is its kVA usage?
• Transformers operate on the principle of what?
• What constant value represents the maximum efficiency in power systems?
• Who is responsible for the operation of cranes on a job site?
• What does the abbreviation FCAN stand for in relation to transformer taps?
• What type of transformer connection involves connecting X1 of one transformer to X2 of another?
• Is copper loss in a transformer power wasted due to the current flow through the windings?
• Which OSHA standard pertains to fall protection training requirements?
• How does a ventilated transformer enclosure interact with air?
• Which of the following loads is a requirement to ensure proper transformer output?
• Which of the following is not an example of a slash-rated three-phase system?
• What signifies that a transformer is operating at an efficient level?
• What device converts electrical energy into a linear force?
• What type of magnet is used for the coil in a relay?
• When DC voltage is applied to a coil (or winding), how does the strength of the magnetic field change?
• When connecting transformers in parallel, which condition must be met for them to share the load properly?
• Is it true that power loss in conductors is wasted energy dissipated as heat?
• What is the kVA rating used by a three-phase load that draws 27.8 amps on a 120/240-volt, three-phase panelboard?
• In Voltage Drop Scenario #7, if the voltage drop is to be limited to 2.3%, what will this amount to in volts?
• If a 480 - 240-volt transformer is connected to a circuit with a voltage of 518, what will be the secondary line voltage without compensating taps?
• In a three-phase AC power system, by how many degrees is each phase offset?
• In a closed-delta transformer bank supplying power to several loads, if the 1-phase loads are drawing 120 amps on AØ and CØ, what is the approximate calculated size required for the "lighting" transformer(s)?
• What is the designated symbol for capacitive reactance?
• What is another term for winding in the context of transformers?
• Which groups of workers are involved with excavation work?
• An AC generator produces how many cycle(s) per revolution for each pair of poles?
• If the current in the primary of a transformer rated at 120 volts and 16 volts is 1.1 amps, how many amps is drawn by the secondary load?
• What is the AØ-to-CØ voltage in a 120/240-volt, 3Ø, 4-W open-delta bank of transformers?
• What output can be produced by connecting three 240 × 480 - 120/240 volt single-phase transformers?
• What type of current constantly changes direction of flow and magnitude?
• Ideally, the power factor (pf) should be kept as close to ___ as possible.
• In a transformer with a 112.5 KVA rating and a primary voltage of 480-volt delta, how many amps flow through each primary winding when the secondary delivers 100 amps to a 3Ø load?
• What surrounds the windings in typical 75 kVA dry-type distribution transformers?
• What would be the output if a buck-boost transformer is incorrectly connected?
• For effective power consumption in a circuit, what should the power factor be closest to?
• In a purely resistive circuit, how is current related to the applied source voltage?
• What can a transformer change its input voltage to?
• What must never be used to operate a hoist for safety reasons?
• When using a 120/240V-16/32V Group II transformer with a 208V input, how much voltage is applied to a control panel requiring 240V?
• Which of the following is necessary for trench safety?
• In a three-phase generator, how are the magnets on the rotor configured?
• In which scenario would you find a wye-delta transformer configuration?
• What is the triplen harmonic associated with odd multipliers?
• For a 480 delta to 120/208 wye transformer connected to a 510-volt supply circuit, what will the line-to-neutral voltage on the secondary be?
• How much current is "seen" by the circuit breaker when the insulation on the "hot" wire is damaged and the impedance of the Sealtite® is 500 ohms?
• Which of the following statements about PCB oils is correct?
• What voltage must the transformer supply to the Main Distribution Panel (MDP)?
• What is the minimum distance a crane must be kept from power lines of 50 KV or less?
• What is a harmonic in electrical terms?
• What is the largest load, in KVA, that any single winding in a transformer must supply?
• Smaller transformers, typically 50 KVA and smaller, operating at or below 600 volts, are normally wound for what type of polarity?
• In the United States, how many times does AC voltage reach a positive peak in one second?
• Dry-type transformer insulation is designed based on an ambient temperature of which degree Celsius?
• How many degrees are in one complete AC voltage cycle?
• What does an operational humming transformer typically mean?
• Which type of winding arrangement does NOT connect the primary and secondary circuits in a transformer?
• When buck-boost transformers are connected to buck the input voltage, how are the primary and secondary voltages affected?
• Larger capacity transformers above 600 volts are typically wound for what type of polarity?
• What is the significance of a neutral connection in a 3Ø generator?
• In a purely inductive circuit, how does the current behave in relation to the applied source voltage?
• In a 480-volt 3-phase circuit connected to the delta primary of a 480 to 240-volt transformer, what is the voltage across any one primary winding?
• If a circuit operates at 277 volts (RMS), what is the peak value of the voltage?
• What happens to magnetic lines of flux when the strength of the magnet increases?
• What type of energy loss occurs in conductors that impacts efficiency?
• Which of the following is true regarding magnetic repulsion?
• How is the secondary of a transformer bank connected that has "X" leads?
• In a series circuit, what happens to the total resistance as more resistors are added?
• What personal protective equipment should be worn when handling PCB transformer oil?
• If a 480 x 120/208 volt transformer is connected to a line with a voltage of 518 volts and compensating taps are not used, what will the secondary line voltage be?
• What is true about signaling a crane?
• In a 3Ø, 480-volt system, a 41 KVA load is located 280 feet from the panel. If K=11.3 and using 8 AWG wire, what is the voltage applied to the load?
• What is the BØ-to-neutral voltage in a 120/240-volt, 3Ø, 4-W open-delta bank of transformers?
• What is the primary purpose of taps in transformers?
• What type of transformer is primarily used for safety in electrical isolation between circuits?
• What is the BØ-to-neutral voltage when a 3Ø, 4-W supply system delivers 120/240 volts?
• Apparent Power is power supplied to a circuit that includes what type of loads?
• What would be the line current if each winding of a 3-phase transformer has a coil current of 60 amps?
• What is an essential requirement for crane operation related to communication?
• In crane operation, why is it important to avoid walking under suspended loads?
• What is the approximate current that would flow through a transformer winding if the AØ and BØ conductors are shorted?
• Which of the following should never be added to a hoist to attempt to lift more load?
• In a single-phase system, what is the total current drawn by a load if the load’s kVA rating is 17.2?
• Which connection type is correct for supplying voltage to a 120-volt load using secondary transformer configurations?
• Which law states that charged bodies attract or repel each other with a force that is directly proportional to the product of the charges?
• A 3-phase transformer bank supplies what voltage to a 3-phase, 4-wire panelboard?
• What is a common output voltage for a solar array before conversion by inverters?
• What component is NOT typically included when calculating impedance in a circuit?
• Using a 120/240V-16/32V transformer, what is the calculated voltage applied to a control panel requiring 208 volts, if the input voltage is 240 volts?
• For a control panel that requires 208 volts and an input voltage of 240 volts, what voltage will be applied using a 120/240V-12/24V transformer?
• In an AC circuit, under what condition are current and voltage in phase?
• What role does a nameplate rating serve in the operation of electrical equipment?
• What is the total kVA of three-phase loads of 16, 42, and 75 amps fed from a 208-volt panel?
• If a transformer has a 480-volt primary and the supply voltage is 468 volts, which tap connection should maintain the rated output voltage?
• In a 480—240-volt 3-wire transformer delivering power to a 3Ø load, what is the current flowing in each circuit conductor if the coil current is 75 amps?
• What unit expresses apparent power?
• What risk is associated with overloaded transformers?
• No guardrails, poor illumination, and no GFCI protection are examples of what?
• What is a fundamental requirement for an electrical system design regarding equipment used during faults?
• What type of load can typically be supported by a .5 KVA transformer rated for 120 x 240 volts when configured correctly?
• Which secondary conductor to the panel carries the most current?
• For a transformer, encapsulation of the windings primarily serves which purpose?
• What role does a transformer play in an electrical system?
• Are transformers capable of converting alternating current to direct current?
• What is defined as the temperature rise in a transformer?
• Who typically manages the one-call center for utility notifications?
• What is the most common trend regarding OSHA construction standards?
• In a trench that is how many feet or more in depth must there be a means of egress within 25 feet?
• Which connection diagram would deliver 220 volts to equipment rated for 220 volts if the supply circuit is 206 volts?
• What determines the necessity for voltage taps on a transformer?
• What is the significance of the nameplate rating of a motor?
• What type of transformer is connected to change supply voltage by ± 15% to deliver proper voltage to the load?
• Is it safe to touch or lean against a crane at any time?
• Which type of transformer enclosure is suitable for outdoor environments?
• If a delta-connected secondary of a transformer is delivering a line current of 54 amps, what is the phase current?
• What type of loads do computers and welders represent?
• What must be ensured before attaching a hoist to a structure?
• Is it feasible to use a Buck-Boost transformer for loads rated at voltages different from the source supply?
• What is the role of secondary windings in a transformer?
• What does BIL measure in a transformer?
• Which of the following is a fundamental characteristic of AC voltage?
• What are the coil voltages in a 3Ø, 4-W supply system delivering 120/240 volts?
• What characteristic of a transformer limits current during a fault?
• What is a device that attracts iron and steel due to molecular alignment called?
• What is the function of a non-linear load like VFDs?
• When calculating the required conductor size for a transformer, what is the essential factor to consider?
• A single-phase 240-volt load drawing 43 amps is connected to a transformer with a primary voltage of 480 volts. How much current is flowing in the primary winding?
• Where should shielded transformers ideally be used?
• What is characteristic of an autotransformer?
• When a 120/240-volt 3Ø, 4-W supply system delivers power, what equals the line current?
• What is the primary function of a buck-boost transformer?
• When a system is designated as delta or wye, what type of system is it indicative of?
• In an electromagnet, what happens to the magnetic field when the current stops?
• In Voltage Drop Scenario #2, the voltage applied to the load is measured at?
• Which electrical principle describes the result of a connected load on the secondary of a transformer?
• What is the minimum ampacity required for primary line conductors if a 300 KVA transformer with a 480-volt delta primary and 240-volt secondary delivers 150 amps to several 3Ø loads?
• How do transformers primarily operate to convert voltage levels?
• Before attaching a hoist to a structure, it is important to ensure that the structure is ___.
• What type of load is specified to be connected to the setup described with a 120/240-volt transformer?
• What is the KVA rating required for a Buck-Boost transformer that can operate a 240-V, 150 A load from a 208-volt supply?
• When a 3Ø, 4-W supply system delivers 277/480 volts, how is the system connected?
• What surrounds the windings in typical "pole-mounted" transformers?
• According to the basic law of magnetism, unlike poles do what?
• When connecting a secondary winding to match a 240-volt load, what configuration is needed?
• Cranes can be operated only by which of the following types of persons?
• ___ is the property of an electrical circuit that opposes any change in current.
• What is the output voltage from a 120/240V-16/32V Group II transformer with proper connections and an input voltage of 240 volts, for a control panel that needs 208 volts?
• Which of the following is a direct measure of the power consumed in a circuit?
• What must be done if an employee can fall through an open hole of 6 feet or more?
• In electrical circuits, when the voltage is increased while maintaining the same impedance, what happens to the current?
• What is the maximum circuit length in feet for a 208-volt load drawing 14 amps using 12 AWG copper conductors while limiting the voltage drop to 3%?
• Which of the following is NOT a common type of crane accident?
• ___ power is the power required to supply both resistive and reactive components of a load.
• What is the correct formula to calculate the equivalent of three inductors in a parallel circuit?
• If a transformer has an efficiency of 95%, how much power must be supplied to deliver 1 kVA to a load?
• Which type of power refers to energy that passes through reactive components without consuming energy?
• Primary power is measured in ___ mW.
• What is the role of a transformer in a distribution system?
• How is power transferred from the primary winding to the secondary winding in a transformer?
• If a transformer requires 32 amps at 480 volts on the primary, what is the efficiency of this transformer if it delivers 120-volt power to a 14.6 kW load?
• Which of the following is not a factor in determining a transformer’s efficiency?
• Which type of equipment is NOT covered under the Powered Industrial Trucks standard?
• What is a safe practice when operating cranes to prevent accidents?
• What component is used to connect the conductors to the "tabs" of a large transformer?
• In a circuit that includes both resistive and reactive components, what determines the total impedance?
• In a 277/480-volt, 3Ø, 4-W supply system, what does the coil current equal?
• What action should not be performed when using a hoist with a load?
• How many volts does a 3Ø, 4-W supply system delivering 120/240 volts provide to the neutral?
• In a typical 3Ø, 4-W wye configuration delivering 277/480 volts, what is the line-to-neutral voltage?
• When are the current and voltage in a circuit considered to be in phase?
• What is the voltage drop percentage for the scenario involving a 19.8-amp, 3Ø load?
• A sine wave represents which kind of signal in electrical engineering?
• Which conversion formula is correct for calculating RMS voltage?
• What does a positive phase angle in an AC circuit generally indicate?
• If 100 volts are applied to a transformer with a primary rated voltage of 120 volts, how many volts will be induced in the secondary rated at 24 volts?
• Inductors in parallel add like resistors in ___.
• What happens if you apply a standard voltage level lower than designated to the primary side of a transformer?
• Which statement about wye-configured voltage systems is accurate?
• What happens to power in a step-up transformer?
• What unit is apparent power measured in?
• How does the current flowing in Line 3 compare to the current flowing in Coil 1?
• When a 3Ø, 4-W supply system delivers 120/240 volts, how is the system connected?
• In a scenario where a 300 KVA transformer delivers power to a 180-amp 3Ø load, what must the primary line conductors be sized to carry at least?
• If the nameplate rating of a 3Ø boiler is 12 KW at 240 volts, what will a meter indicate in amps?
• What is typically true about the relationship between inductive and capacitive reactance in an AC circuit?
• What is the purpose of a transformer in electrical systems?
• What does the OSHA subpart on Fall Protection outline?
• What is the voltage applied to Heating Element A in the system?
• What is the total kVA load when a 240-volt 15 kW load and a 120-volt 10 kW load are connected simultaneously?
• What is the maximum kVA of power that a bank of transformers using 100 KVA transformers can deliver?
• In a series circuit with equal inductive and capacitive reactance, what is a true statement?
• What occurs when buck-boost transformers are connected to boost the input voltage?
• If a 3Ø 240-volt load is supplied by a 100 KW generator and the load's nameplate rating is 59.2 kVA, what is the current in amps?
• Which of the following statements is true regarding transformers?
• Capacitor banks are rated in which of the following units?
• How does the current flowing in Line 3 relate to the current in Motor Winding B?
• What causes current to flow in the connected load on the secondary of a transformer?
• For a delta bank serving mostly 120-volt loads, how much current must each transformer supply?
• Ignoring losses, what remains constant on both sides of a transformer?
• In a series circuit with inductive reactance less than capacitive reactance, what will current do in relation to voltage?
• How many amps can a bank of three 100 KVA transformers deliver to a building service if one transformer fails?
• What do K-rated transformers do in relation to harmonic currents?
• In a 3Ø transformer bank, when primary voltage is applied, which output voltage is expected?
• When using a hoist, the load should be moved with ___ motion to ensure safety.
• What is indicated by an increase in current through a coil in terms of magnetic field strength?
• An open-delta bank of transformers delivers what type of power?
• The peak-to-peak value of a sine wave is how many times the maximum positive peak value?
• In a three-phase system, if one coil is energized, how is the current distributed among the coils?
• What type of energy do inverters convert to AC?
• Is the following statement true or false? True power will always be greater than apparent power.
• How does the voltage rating of a generator affect its current output?
• What is the typical efficiency of transformers?
• In a balanced load connected to a delta-connected transformer, what is true about the coil currents?
• Which two components affect current flow in an AC circuit?
• What is one of the typical materials used in dry-type transformer insulation?
• A change in the magnetic field surrounding a conductor induces a voltage in the conductor. What is this induced voltage known as?
• A resistor is an example of what type of power?
• If a transformer has a delta primary and a wye secondary, what is this transformer called?
• A charged body is surrounded by what type of field?
• How is the effective value of AC voltage commonly calculated?
• Hoist equipment is primarily used to assist in ___ large or heavy equipment.
• With each complete cycle of AC voltage, how do the voltage values behave in relation to time?
• Which of the following includes all unsafe acts?
• What type of transformer is designed specifically to handle high electric loads without overheating?
• What is the line-to-line voltage of a 3Ø, 4-W supply system that delivers 277/480 volts?
• What is the maximum line current a 500 KVA 480-volt three-phase delta secondary transformer can deliver without exceeding its rating?
• Which factor primarily affects the current carried by a circuit conductor?
• All circuit conductors contribute what to a circuit?
• What type of transformer is routinely used where "clean power" is required to operate delicate electronic equipment?
• What characterizes the behavior of an inductive circuit in relation to voltage?
• When the line-to-line voltage at the service equipment drops to 456 volts for a 277/480-volt 3Ø, 4W service, what is the actual line-to-neutral voltage available?
• If a transformer's primary is rated at 120 volts and its secondary at 12 volts, what is the turns ratio?
• What is one of the most common types of crane accidents?
• What characteristic does the oil in oil-filled transformers provide?
• Which of the following practices can help eliminate unsafe acts?
• Which formula is correct to find the equivalent of 3 capacitors in a parallel circuit?
• In a purely capacitive circuit, how is current related to the applied source voltage?
• For a transformer to function properly, it should operate within what limitations?
• What type of connection is characterized by a 3Ø, 4-W supply system delivering 120/208 volts?
• Lockout/Tagout devices should identify the ___.
• If a transformer rated at 15 KVA has secondary windings rated for 120/240 volts and several 120-volt loads are connected, what is the maximum current it can supply to those loads?
• What type of voltage taps can be found on a three-phase transformer?
• What is the maximum current that a 32 KW, 480-volt generator can deliver to a load?
• When operating a hoist, it is critical to avoid allowing anyone under a ___ load.
• In a three-phase delta system, if the line current is known, how do you find the phase current?
• For an AC circuit to have current and voltage in phase, what condition must be met?
• For a 3Ø, 3-W system delivering 240 volts, which configuration is typically used?
• True power is defined in relation to which of the following?
• What must be determined before the opening of any excavation?
• The output voltage of a buck-boost transformer is influenced by which of the following?
• What voltage will a piece of foreign-made equipment rated for 220 volts receive if the supply circuit voltage is 206 volts and Diagram 4 is used to connect a transformer?
• In what unit is true power measured?
• What is the minimum rating required for a transformer bank supplying a 3Ø, 45 KVA load?
• How many amps does a 15 kVA transformer supply to a 11.5 kW 120-volt load?
• If a 25 kVA transformer with 120/240-volt secondary windings is connected to a 240-volt load, what is the maximum amps it can deliver?
• What type of transformer has no direct electrical connection between the primary and secondary windings?
• What does the abbreviation RMS stand for?
• In which scenario would it be inappropriate to use a buck-boost transformer?
• What should be done if an employee repeatedly ignores safety signage?
• A transformer with a primary rated at 240 volts and a secondary rated at 120 volts is supplying a load pulling 10 amps. How many amps flow in the primary circuit?
• What is the primary role of hoist equipment in construction or industrial settings?
• Which of the following describes a dual-voltage secondary in a transformer?
• In a corner-grounded delta system, what is the grounded conductor commonly referred to as?
• A capacitor is made up of a pair of conductive plates separated by what type of material?
• What would be the effect on an electrical panel if a tool were shorted across the busbars?
• How much does it cost to operate a clothes dryer rated at 6,700 watts for 6 hours at a utility rate of 10.09 cents per kW-hr?
• What is the characteristic feature of the peak of a sine wave?
• The loss of power due to resistance in wires is known as ___ losses.
• What can be a consequence of unsafe acts on a job site?
• For a system that requires a load to operate at 12 volts from a higher primary voltage, what configuration would the transformer take?
• What connection type would be used for transformer windings rated at 120/240 volts when supplying power to a load with that same rating?
• What is the measure of a circuit's ability to store an electrical charge called?
• Which components are used to correct power factor in a circuit?
• What happens to power when it is transferred in a transformer?
• Cranes are primarily used to lift and place what?
• How many average deaths per year are contributed to accidents involving excavating and trenching?
• What happens if the applied primary voltage is below the rated voltage on a transformer?
• What defines the term "impedance" in an electrical circuit?
• What is the designated symbol for inductive reactance?
• A single-phase, 208-volt load drawing 14 amps with 12 AWG copper conductors cannot exceed what circuit length to limit the voltage drop to 3%?
• Under what condition should buck-boost transformers be used for voltage drop correction?
• When a 3Ø, 4-W supply system delivers 120/208 volts, how is the system connected?
• When transformers are installed to meet a customer's voltage needs, what can they be configured to do?
• After witnessing unsafe acts or conditions, which actions should you take?
• A transformer with a ___ enclosure is permitted to be installed inside a building.
• Which of the following is considered an unsafe act?
• What type of system is formed when a 3Ø generator has a neutral connection?
• A step-down transformer's secondary winding is connected to what?
• Which systems can provide safety on construction sites involving heights and potential falls?
• In a 480 to 120/208-volt wye transformer supplying a 3Ø load with 75 amps of coil current, how much current flows in each circuit conductor to the load?
• In a 100 Hz circuit with a 15 mH inductor, what is the inductive reactance in ohms after converting millihenrys to henrys?
• Which symbol is commonly used to represent an inductor in a schematic circuit?
• What is a common method for cooling transformers?
• For efficiency, what type of construction is preferred for transformer cores?
• What is the primary function of a transformer in an electrical circuit?
• A transformer with a nameplate rating of 240/480-V primary can deliver nameplate-rated voltage to a load when connected to what type of breaker?
• Which of the following systems is responsible for ensuring worker safety at heights?
• Within the context of electrical work, what safety measure is crucial regarding load management?
• What are the potential unsafe acts that can occur on construction sites?
• True or False: The voltages induced in each secondary winding of a single-phase transformer with a dual-voltage secondary are equal.
• Which type of connection is required for a 120/208-volt, 3-ph, 4-wire secondary transformer system?
• What happens when two unlike poles of magnets are brought together?
• Which of the following is a type of electric power generating plant?
• What is commonly established to notify utilities of planned excavation?
• What is the AØ-to-neutral voltage in a 120/240-volt, 3Ø, 4-W open-delta bank of transformers?
• If the output of a 3Ø generator is 208 volts line-to-line with a neutral connection, what type of system is it?
• In an AC circuit containing resistance and reactive components, what is the term used for the opposition to current flow?
• In an inductive circuit, what happens to the current when the voltage is increased?
• What is the result of applying voltage below the rated primary voltage to a transformer?
• Which unsafe act would likely lead to accidents near machinery?
• How many types of cranes are there?
• If a CT has a current ratio of 500:1 and indicates 67 mA, what is the current in the primary circuit conductor?
• What term describes the process by which a coil of wire can generate a magnetic field when current flows through it?
• What voltage is delivered by each transformer in a bank when rated primary voltage is applied?
• Which connection method allows for voltage regulations through a standard transformer in a 120/240-volt system?
• If the current flowing through a coil of wire is increased, what happens to the magnetic field strength?
• What is the property of an electrical circuit that opposes any change in current?
• Power is measured in ___.
• What happens to the strength of the magnetic field around a coil when AC voltage is applied?
• Are distribution transformers designed to deliver voltages that are useable at that voltage level?
• With current flowing in the primary circuit, what voltage is induced on the secondary winding of the pole-mounted transformer?
• What does the vertical axis on a voltage sine wave represent?
• What principles do motors, circuit breakers, contactors, relays, and motor starters use?
• During peak periods, if 100 amps flows through the conductors and 44 amps normally flows with 19.36 kW power loss, what are the I2R losses in the conductors?
• Polarity is primarily associated with what type of transformers?
• Which component often does not mitigate problems related to harmonic distortion?
• What is the voltage applied to the load in Voltage Drop Scenario #7?
• Most transformers designed for use outside the United States and Canada generally operate at which frequency?
• What would likely happen if a buck-boost transformer is used without considering load conditions?
• Which of the following accurately describes how a harmonic impacts electrical systems?
• Where do distribution lines typically run?
• The frequency of AC voltage in most household circuits is typically what?
• When a transformer's windings are encapsulated, the resin encapsulation performs which of the following functions?
• How much current will each circuit conductor feeding Circuit LB-7,9,11 carry?
• What is a potential hazard of inadequate trench safety measures?
• What is the current flowing in the feeder conductor if all loads are operating in a 3-pole breaker scenario with a 30 kVA load?
• Which configuration of transformer does NOT affect frequency?
• Is the current flowing in generator Coil 1 equal to the current flowing in Motor Winding A?
• To supply a 120 VA load connected to the secondary of a 250 VA transformer, how much power must be supplied on the primary?
• For a 3Ø, 4-W system delivering power at 480 volts, what is true about its winding current?
• Dry-type distribution transformers are equipped with ___ to reduce mechanical noise.
• If a 3Ø generator outputs 240 volts line-to-line with a neutral connection, what type of system is it?
• What is the current that each circuit conductor to a 48 KW, 240-volt boiler will carry?
• What is the relationship between power loss and transformer design?
• For standardization, how many steps above or below the nameplate rated voltage are transformers manufactured with taps?
• Which transformer winding typically has the largest load in amps?
• When working with cranes, what is a critical safety practice to follow?
• If the transformer bank's secondary windings are connected in series, what configuration is used?
• Inductance is measured in which unit?
• What is an important consideration when connecting multiple buck-boost transformers in parallel?
• What does PPE stand for in the context of construction safety?
• Which of the following best describes the function of a 3Ø, 4-W transformer system?
• A coil of wire wrapped around an iron core acts as what when it carries current?
• Which of the following best describes unsafe rules?
• What is the output voltage if the secondary windings of a transformer rated 120/240 are connected in series?
• In a three-phase four-wire delta system, what is the B-phase conductor commonly referred to as?
• Which voltage reduction method is achieved by connecting a transformer as an autotransformer?
• What is the term used to describe one billion cycles per second?
• What is the purpose of transformers for utility companies in power transmission?
• To support a 29 amp load at 208 volts from a properly connected transformer, what size KVA transformer is needed?
• What is the function of ventilation in large dry-type transformer enclosures?
• When capacitive and inductive reactance are equal, what is the result on the circuit?
• ___ is the ratio of the actual power delivered by a load divided by the input power required by the load to operate.
• What type of soil poses a greater risk during excavation?
• What is the coil voltage in a 120/208-volt, 3Ø, 4-W supply system?
• What aspect of crane operation is emphasized to ensure safety?
• What is the line voltage when a 120/240-volt, 3Ø, 4-W open-delta bank of transformers delivers power to a load?
• How do non-linear loads behave with respect to the applied voltage wavelengths?
• Total opposition to current flow in an AC circuit is referred to as what?
• In a typical transformer setup, the heater loads are generally connected to which configuration?
• What is essential for creating a powerful electromagnet?
• A 3-phase load that requires protection from falling must have what type of systems in place?
• What type of load can a transformer with a 120/240-volt secondary be connected to?
• In Voltage Drop Scenario #7, the voltage dropped in the circuit conductors is what percentage?
• Which term best describes the voltage that fluctuates over time and can be represented as a sine wave?
• What is the voltage across each winding of a wye-connected transformer secondary that has a line-to-line voltage of 480 volts?
• What does the horizontal axis on a voltage sine wave represent?
• What is the voltage ratio of a transformer with a primary voltage of 120 volts and a secondary voltage of 24 volts?
• What must be ensured before a crane is operated near power lines?
• What should be the motion used for moving a load with a hoist?
• Which component is essential for preventing falls from unprotected edges in a construction zone?
• What is an example of an autotransformer?
• For a 120/240-volt load, which connection should be used from the transformer?
• What is the significance of the two standards related to Fall Protection?
• To ensure system stability, what should an electrical designer consider when selecting transformers?
• How are heat losses in electrical systems typically measured?
• For a 50 Hz circuit with a 25 µF capacitor, what is the capacitive reactance in ohms after conversion?
• What is the result of overloading a transformer?
• Transformer power ratings can be expressed in which of the following units?
• What voltage is supplied to a control panel that requires 240 volts if the input voltage is 208 volts?
• If a 3Ø motor has a nameplate rating of 60 KVA at 240 volts, how many amps will a meter indicate?
• In a 60 Hz circuit with a 1.3 mH inductor, what is the inductive reactance in ohms after conversion?
• Which component is primarily responsible for energy storage in an AC circuit?
• A 480 delta to 120/208 wye transformer connected to a 510-volt supply circuit will result in what line-to-line voltage on the secondary side?
• In an induction motor circuit, the apparent power is ___ the true power delivered by the motor.
• From which breaker in a 3Ø panelboard will there be 208 volts to ground when powered by a 3Ø transformer supplying 120/240 volts?
• True power is defined as power consumed by a resistor and dissipated as heat, which is not returned to the generation source. What is true power measured in?
• What is the voltage dropped in the circuit conductors of Voltage Drop Scenario #2?
• Which OSHA standard is the most frequently violated in construction work?
• Using a 50 KVA transformer with a 2.8% impedance, what is the current flowing through a 4/0 AWG jumper when X1 and X4 are connected?
• A 1Ø transformer rated at 37.5 KVA supplies power to a 22 KVA load at 240 volts. How many amps is the transformer supplying to the load?
• Can transformers change an input frequency of 60 Hz to an output frequency that is 10% higher or lower?
• When replacing a transformer, how should the new transformer be sized in relation to the existing load?
• Can a buck-boost transformer be used as an isolating transformer for low voltage control circuit?
• Which drawing indicates an autotransformer connection?
• In AC circuits, what angle is noted for determining phase differences between multiple phases?
• What reading would be shown on an ohmmeter between connection points X1 and H2 in a transformer winding?
• The minimum calculated size of a transformer when sizing at 125% of an existing load of 79.2 kVA is what?
• When would you utilize taps on a primary transformer?
• In a three-phase transformer, applying a voltage higher than the nameplate rated voltage to the primary results in what?
• The ___ capacity of a hoist indicates whether it can lift the intended load safely.
• What is the voltage dropped in the circuit conductors in the Voltage Drop Scenario #7?
• How many years can a transformer be expected to operate when within its ratings?
• In a three-phase system, what is true about the voltage between any two ungrounded conductors?
• What happens when a capacitor is connected in series with a resistor?