Prepare for your Electrician License exam with these practice questions and answers. This guide covers National Electrical Code (NEC), circuit calculations, motor controls, transformers, and electrical theory.
Q: Why can a lead acid battery be an explosive hazard?
Answer: Hydrogen gas is produced during charge and discharge.
Q: When a megger is used to check electrical equipment before initial energizing, the electrician will ensure that the phase conductors are free from cuts or abrasions in the insulation by checking?
Answer: Phase to phase and phase to ground.
Q: Why should the test leads of a megger never be touched when in use?
Answer: The generator voltage is present on test leads and could result in electric shock.
Q: A drawing showing point A to point B hookup of conductors is called?
Answer: Wiring diagram.
Q: How much power is consumed in a circuit with a voltage input of 120V and an R-Value of 40 ohms?
Answer: 360 Watts
Q: What test equipment can be used to conform a suspected short circuit or ground fault in a 3-phase circuit
Answer: Megohmmeter
Q: Normally, the easiest place to reverse the leads to change the direction of the rotation of a 3-phase motor is at the?
Answer: Motor starter
Q: What type of conduit fitting is usually placed in the middle of a long run of rigid metal conduit to provide access for pulling wire?
Answer: C fitting
Q: The frequency of a circuit is 15 cycles per 1/4 second, what is the Hertz(HZ) rating of the circuit?
Answer: 60Hz
Q: Several #12 AWG conductors are pulled together, how should they be arranged on the fish rope?
Answer: Staggered
Q: What is the multiplier for calculating a 45 degree offset when conduit is being bent?
Answer: 1.414
Q: Four-inch square boxes are available with all of the following depths except?
Answer: 1 inch
Q: Which of the following is used to connect a 1/2 inch drain to the bottom of a 3/4 inch tee?
Answer: 3/4″ X 1/2″ RE
Q: What is a system of grounding electrodes interconnected by grounding conductors that are buried in the earth to provide lower resistance?
Answer: A ground grid
Q: Splicing is permissible on all of the following conduit bodies except?
Answer: Pulling elbows
Q: The first step in making an exothermic (cad weld) connection is to?
Answer: Prepare the cable mold and the welding material
Q: What type of switch will provide three-point control for a light?
Answer: Two 3-way switches and one 4-way switch
Q: A switch labeled CO/ALR can be used with what type of wire?
Answer: Aluminum, copper or copper-clad aluminum
Q: What is shown on a sectional drawing?
Answer: Cutaway view of a building
Q: The type of drawing that shows the general arrangement of service entrance equipment and panel boards, along with the related services and feeder conduit/conductors is a?
Answer: Panel board schedule
Q: The ratio of power in watts to the total volt-amps of an AC circuit is known as?
Answer: Power factor
Q: Why should the proper rope be selected for a cable pull?
Answer: To maximize safety
Q: What is the main purpose for a dynamometer?
Answer: To read pulling tension
Q: What size wire is standard for 120-volt motor control systems?
Answer: #14 AWG
Q: How is a transformer rated for power output?
Answer: Kilovolts-amperes (KVA)
Q: Which of the following conductors has the least resistance?
Answer: 1/0 AWG
Q: What is the amperage in a 24-volt circuit with 4 ohms of resistance?
Answer: 6 Amps
Q: What are the two most common types of overcurrent protective devices?
Answer: Circuit breakers and fuses
Q: Under normal conditions, how does voltage measured between line and neutral of a 3-phase, 4-wire “Y” system compare to voltage measured line to line?
Answer: Less
Q: The potential across the circuit is 480 volts and the current is 50 amps. What is the resistance of the circuit?
Answer: 9.6 ohms
Q: Which of the following carries power from a main panel board to various subpanels?
Answer: Feeders
Q: What is an acceptable protection technique for electrical equipment in hazardous locations?
Answer: Use dust ignition proof equipment
Q: The trip rating of a circuit breaker used as the main protective device in a panel board can not exceed?
Answer: The amperage capacity of the bus bars in the panel board
Q: A heat trace cable is installed on a line that will be insulated. When will the cable be megged?
Answer: Before and after insulation is put on the line
Q: What type of enclosure is approved for general purpose indoor use and not dust or drip proof?
Answer: NEMA 1
Q: When is a seal not required in a conduit entering a switch in a class 1, Division 1 location
Answer: When the chamber is hermetically sealed
Q: What would be found in a class 1 location
Answer: Five threads on conduit connections
Q: In a class 1, division 1 area, what type of electrical fittings are required?
Answer: Dustproof
Q: What does a solenoid do?
Answer: Actuates a pneumatic control valve
Q: Which of the following types of fuses is best for protecting a motor feeder?
Answer: Dual element time-delay
Q: All of the following are components of a conventional circuit breaker except?
Answer: A link capable of melting under overload
Q: All of the following are reasons a split phase may not start except?
Answer: Improper air gap
Q: What do thermal overloads protect in a starter?
Answer: Motors
Q: Which of the following statements about a tapped transformer is true?
Answer: It has several terminal taps on the primary to allow for voltage adjustment
Q: In a 3-phase, 4 wire, 120/240 volt delta-connected service, what is the high leg’s voltage to ground?
Answer: 120 volts
Q: What term describes the components located between the service drop and the main disconnect?
Answer: Service entrance
Q: While reels of cable are being stored, what is the purpose of sealing cable ends?
Answer: To keep moisture from creeping in
Q: Which of the following inscriptions on a circuit breaker indicate that the circuit breaker is designed for use on both copper and aluminum wire?
Answer: CU/AL
Q: How is a voltmeter connected in a circuit?
Answer: Series or parallel
Q: While following normal lockout/ragout procedures, who is authorized to remove the lock and tag?
Answer: Only the employee who initiated the lockout/tagout
Q: What is the purpose of a lockout/tagout
Answer: Prevents operation
Q: Where the GFCI be installed when using an extension cord
Answer: At the receptacle
Q: Until determined otherwise, all electrical equipment and conductors should be considered?
Answer: Energized
Q: Which of the following statements describes a parallel circuit?
Answer: All of the loads are connected in a separate path
Q: What is indicated by a one-line diagram with simplified symbols?
Answer: Interconnections and component parts of an electrical circuit
Q: What type of conduit body has a threaded straight hub on each end?
Answer: C fitting
Q: A type LB conduit body has the cover on?
Answer: The back
Q: What is type USE cable primarily used for
Answer: Direct burial in the earth
Q: What type of wire is standard for low-voltage milliamp signal systems?
Answer: Single pair shielded
Q: What is a CT and what is it used for?
Answer: Current transformer and used to measure amps
Q: The relationship of the transformer primary winding to the secondary winding is expressed in?
Answer: Turns ratio
Q: In a sine wave, the number of times per second an Identical pattern repeats itself is known as the?
Answer: Frequency of a wave form
Q: A Myers hub is used to?
Answer: Provide a rain-tight seal where a run of enters a junction box
Q: Which of these sets of receptacle terminal color codes and wire color codes is correct?
Answer: Green terminal-ground wire; silver terminal-white conductor; brass terminal-black conductor
Q: Which of the following switch combinations are correct for controlling a light from three different positions?
Answer: Two 3-way switches and one 4-way switch
Q: What article of the NEC covers grounding?
Answer: Article 250
Q: Where is nonmetallic conduit (PVC) used
Answer: Both below and above ground
Q: What is produced in a conduit run by making two equal bends in opposite directions
Answer: Offset
Q: According to NEC section 406.3(A), which of the following branch circuits must have grounded receptacles?
Answer: 15A and 20A branch circuits must be of the grounding type
Q: What is the voltage ratio for dual-voltage motors
Answer: 2 to 1
Q: What is the area of a rectangular piece of material 4 feet by 10 feet
Answer: 40 square feet
Q: What is a fish tape used for
Answer: Pulling wire or rope through conduit
Q: Cable trays are usually supported by all of the following means except?
Answer: #9 wire
Q: What is installed at an expansion joint to provide a continuous ground between two sections of cable tray?
Answer: Bonding jumpers
Q: What is used to make a slight change in elevation in a cable tray system
Answer: Swivel plates
Q: When locations for junction and pull boxes are selected, all of the following should be considered except?
Answer: Type of conductor to be installed
Q: PVC conduit, fittings, and connectors range in size from 1/2″ to?
Answer: 6 inches
Q: Which of the following components is part of a dual element fuse?
Answer: Time delay
Q: Service entrance conductors May be spliced only when?
Answer: Taps are being made to each of the service disconnects
Q: What does the thermal overload protect in a starter or MCC
Answer: Motors
Q: A cable rated for 5 KV can safely carry what maximum voltage?
Answer: 5,000 volts
Q: How should heat-shrink insulators be installed?
Answer: The insulator should be slipped over the connector and heat should be applied for a few seconds
Q: Which of the following is one way to control voltage at a substation
Answer: Potential transformer
Q: A motor control center is a group or combination of?
Answer: Starters in a single enclosure
Q: What does HOA usually mean in a motor control circuit
Answer: Hand-off Automatic
Q: Where the overload heaters normally located in a motor circuit?
Answer: In the motor starter between the T leads and the contactors
Q: Where should a stress cone be used?
Answer: High voltage termination
Q: When making a high-voltage splice all of the following are part of the splicing procedure except?
Answer: Hi-pot testing
Q: Which of the following statements about resistance heat tracing is true?
Answer: They are self-regulating
Q: All of the following are basic elements of a motor circuit except?
Answer: A motor control center
Q: What happens when the seal-in (holding) contact on a motor starter is opened?
Answer: The motor will stop
Q: What does the typical control transformer do in a motor starter?
Answer: Provides power to the control circuit
Q: What should be done to change the rotation of a 3-phase motor?
Answer: Swap any two T-leads
Q: All of the following guidelines shall be met in order to use the 10′ Tap Rule except?
Answer: The amperage if the tap conductors shall not be less than the load served
Q: Blue prints require the installation of a 277-volt 15-amp switch and a 120-volt, 15-amp switch in the same box. Which of the following is required?
Answer: The proper separation plate must be installed
Q: The primary of a transformer is 480 volts and the secondary is 240/120
Answer: On the secondary
Q: Given: The distance between a starter and a 3-phase motor is 73 feet. The starter must have a 5 foot tail and the motor a 3 foot tail. How much multi-conductor wire is required for a pull from the starter to the motor?
Answer: 81 feet
Q: An improperly made wire splice or connection could result in all of the following except?
Answer: Improper current flow of the conductor
Q: What is the most common service voltage used in a temporary power panel?
Answer: 120/240 volt, 1-phase, 3-wire
Q: A section of cable tray that makes two vertical 90-degree turns is known as?
Answer: A vertical tee
Q: What does capacitance permit the capacitor to do?
Answer: Store an electrical charge
Q: The minimum acceptable DC megohm resistance of a 4, 160 volt motor is approximately?
Answer: 4.2 megohms
Q: What is the source voltage in a circuit that consumes 1,200 watts at a current of 5A?
Answer: 240 volts
Q: How many amperes will flow in a circuit containing only resistance if the resistance is 10 ohms and the voltage is 120 volts?
Answer: 12 amps
Q: All of the following are correct formulas for ohms law except?
Answer: E= PxI
Q: The purpose of the OSHA lockout/tagout procedure is to ensure that?
Answer: Equipment and individuals are isolated from all potential hazardous energy
Q: Which of the following type of clothing should not be worn while performing electrical work?
Answer: Polyester
Q: Which of the following conditions must indoor switchgear be protected against?
Answer: Moisture
Q: What is required at the Xo terminal of a transformer?
Answer: Must be bonded and grounded
Q: Which of the following is used to connect the grounded conductor to a grounding electrode?
Answer: Grounding electrode conductor
Q: All of the following are purposes of grounding and bonding except?
Answer: To help stabilize voltage between the underground conductors
Q: Which of the following is considered a standard fuse size?
Answer: 3
Q: What unit is true power measured in?
Answer: Watts
Q: Which of the following transformers are connected in series?
Answer: Current transformer
Q: If the turn ratio of a transformer is 4000:5, and the primary voltage is 2000 volts, what is the voltage on the secondary
Answer: 2.5
Q: To make a 10″ offset on a 15° angle, how far apart must the center of your bends be?
Answer: 38.6″
Q: All of the following are acceptable for use in guardrails in a guardrail system except?
Answer: Rooe
Q: What is a grounded conductor?
Answer: Neutral
Q: What all can a multimeter test for?
Answer: Voltage, current, resistance
Q: What is the peak value of a 120V circuit?
Answer: 170V
Q: What is used to bypass and discharge electrical surges?
Answer: Surge protector
Q: What is the minimum distance that must be maintained in between ground rods?
Answer: 6 feet
Q: In a 3-wire push button start/stop circuit, which set of contacts are normally closed
Answer: Stop
Q: Which type of conduit is most suitable for a corrosive environment?
Answer: Aluminum
Q: What must the neutral of a subpanel be?
Answer: Ungrounded
Q: Which of the following is the minimum required length of a ground rod?
Answer: 8 feet
Q: What does E stand for in ohms law?
Answer: Voltage
Q: In a motor starter, the seal-in auxiliary is considered to be connected in what way with the start button?
Answer: Parallel
Q: How much larger must a pull or junction box be used when making a U-Pull?
Answer: 6 times bigger than the raceway
Q: What size must a junction box be with two 4″ conduits, one 2″ conduit and two 1″ conduits entering it for a straight pull?
Answer: 32″
Q: How much larger must a pull or junction box be when making an angle pull?
Answer: 6 times the largest raceway
Q: When combustible vapors are present, which hazardous location is it considered?
Answer: Class 1, division 1
Q: When inspecting rubber insulated gloves daily the two things to check are the voltage rating and?
Answer: Pin holes
Q: Which type of heat trace cable can not be cut to length in the field?
Answer: Mineral insulated
Q: When bending a 90° stub up using 15° segment bends, how many bends must be made?
Answer: 6
Q: When facing the busbar of a panel, in respect to A and B phase, where is C phase located?
Answer: To the right
Q: How is heat trace cable positioned when installed for anti freeze protection?
Answer: Circular
Q: How many overload units are required for a 3-phase motor?
Answer: 3
Q: What type of conduit support can be used to prevent making an offset into a conduit fitting/box?
Answer: Stand off support
Q: For 4/0 and larger wire, what is used to determine the minimum cable tray width?
Answer: Diameter
Q: For wire smaller than 4/0, what is used to determine the minimum cable tray width?
Answer: Cross sectional area
Q: Plastic and porcelain are examples of?
Answer: Insulators
Q: What is the color code for #22-#16 AWG wire crimp connectors?
Answer: Red
Q: What is the material between the capacitor plates in which the electric field appears?
Answer: Dielectric
Q: Which of the following is used to alter the speed of a 3-phase squirrel cage induction motor?
Answer: Frequency
Q: One circular mil is how many inches
Answer: 0.001″