Journeyman Electrician Practice Test 37

Question 1: Which of the following is not a nominal system voltage that should be used to compute branch circuit, feeder and service calculations?

• 120
• 120/240
• 208Y/240
• 208Y/120

NEC Reference: NEC 220.5(A)

Question 2: A 75 feet, 120/240 volt single-phase service is connected between the service point and a panelboard. The operating current is 60 amperes, and the total (out-and-back, both conductors combined) resistance of the service conductors is 0.2 ohms per 1000 feet. What is the voltage at the panelboard?

• 239.1 volts
• 240 volts
• 238.5 volts
• 238 volts

Question 3: Four household electric ranges, each rated 12 kW, are on one feeder. What is the demand load from Table 220.55, Column C?

• 14 kW
• 17 kW
• 20 kW
• 48 kW

NEC Reference: NEC 220.55 and Table 220.55, Column C

Question 4: A 12 volts battery is connected group of four parallel resistors each with 4 ohms. How much current does the circuit draws from the battery?

• 12 Amperes
• 3 Amperes
• 8 Amperes
• 24 Amperes

Question 5: A lamp with wattage of 20 watt draws 0.5 ampere current. What is its operating voltage?

• 40 volts
• 10 volts
• 20 volts
• 80 volts

Question 6: What is the corrected ampacity of a 2/0 AWG THWN-2 conductor installed in a conduit in a dry location, if the ambient temperature at that location is 45°C?

• 170 Amperes
• 188 Amperes
• 139 Amperes
• 160 Amperes

NEC Reference: NEC Table 310.16

Question 7: Tank storage installations inside buildings below grade level are classified as _____.

• Class I Zone 1
• Class II Zone 1
• Class I Division 1
• Class I Zone 2

NEC Reference: NEC Table 515.3

Question 8: Which component stores energy in an electric field between two plates?

• Inductor
• Resistor
• Fuse
• Capacitor

Question 9: Besides the ampacity tables, how else does the NEC permit conductor ampacities to be determined?

• By calculation under engineering supervision
• From the manufacturer's catalog only
• There is no other method allowed
• By the installer's own judgment

NEC Reference: NEC 310.14(B)

Question 10: Instrumentation tray cable (Type ITC) may NOT be used on circuits operating at more than 150 V or more than how many amperes?

• 5 A
• 10 A
• 15 A
• 20 A

NEC Reference: NEC Article 335

Question 11: In a load calculation, the result is 47.4 A. How may the fraction be handled?

• It must always be rounded up to 48 A
• Under 0.5 may be dropped: 47 A
• It must be doubled for safety
• It must be rounded to the nearest 5 A

NEC Reference: NEC 220.5(B)

Question 12: Overhead 120/240-volt service conductors pass over a sidewalk accessible only to pedestrians. What is the minimum clearance?

• 15 ft
• 12 ft
• 10 ft
• 8 ft

NEC Reference: NEC 230.24(B)(1)

Question 13: A GEC is attached to fireproofed structural steel by an exothermic weld. Must that connection remain accessible?

• No; those connections are exempt
• Only if it is inspected every year
• Yes; every electrode connection must be accessible
• Only in dwelling units

NEC Reference: NEC 250.68(A) Exception No. 2

Question 14: A feeder supplies two motors: Motor A has a full-load current (FLC) of 20 amperes and Motor B has an FLC of 10 amperes. Per NEC 430.24, the minimum feeder conductor ampacity is _____ amperes.

• 30 amperes
• 35 amperes
• 37.5 amperes
• 40 amperes

NEC Reference: NEC 430.24

Question 15: A 4-wire, 3-phase wye feeder supplies a large amount of electronic (nonlinear) load. May the 70% neutral demand factor for loads over 200 A be applied to that portion?

• Only for loads below 200 A
• Yes, always
• Only for dwelling units
• No; not for the nonlinear portion

NEC Reference: NEC 220.61(C)

Question 16: Per NEC 110.27(A), one acceptable method of guarding live parts against accidental contact is elevating them to a height of not less than _____ above the floor or working platform.

• 6 feet
• 7 feet
• 8 feet
• 10 feet

NEC Reference: NEC 110.27(A)

Question 17: What does 500.4(A) require for areas designated as hazardous (classified) locations?

• Painted yellow on the floor
• Reported to the serving utility
• Documented and available to authorized persons
• Nothing beyond warning signs

NEC Reference: NEC 500.4(A)

Question 18: Which type of motor has a commutator and brushes?

• Synchronous reluctance motor
• DC motor (and AC universal motor)
• Squirrel-cage induction motor
• Shaded-pole motor

Question 19: What is the peak voltage of a 120-volt (RMS) sine wave?

• 85 V
• 120 V
• 170 V
• 240 V

Question 20: Which AC system of 50 to 1,000 V is NOT required to be grounded (250.21(A))?

• A 480Y/277-volt system with neutral loads
• A 120/240-volt dwelling service
• A 208Y/120-volt system
• One supplying only industrial melting furnaces

NEC Reference: NEC 250.21(A)

Question 21: Instead of individual GFCI receptacles, how else may the GFCI protection required by 210.8 be provided for several branch circuits?

• A GFCI protecting the feeder
• A surge-protective device
• It cannot be done any other way
• An AFCI breaker on each circuit

NEC Reference: NEC 215.9

Question 22: What does it mean that circuit breakers must be "trip free"?

• They can be held closed during an overload
• They trip even if the handle is held ON
• They trip only by hand
• They never need to be reset

NEC Reference: NEC 240.80

Question 23: Which of these circuits is NOT permitted to be grounded?

• Cranes over combustible fibers (Class III)
• A 120-volt general lighting circuit
• A 208Y/120-volt feeder
• A 120/240-volt dwelling circuit

NEC Reference: NEC 250.22

Question 24: Two dwelling units are supplied by one feeder. Under 220.85, which load may be used if the standard calculation exceeds the optional result for three identical units?

• 125% of the standard load
• Their sum
• The lesser of the two loads
• The larger of the two

NEC Reference: NEC 220.85

Question 25: A No. 4 AWG THWN-2 conductor is installed in a conduit inside a boiler room where the ambient temperature is 50°C. The base ampacity from NEC Table 310.16 (90°C column) is 95 amperes. Using the correction factor of 0.82 from NEC Table 310.15(B) for 50°C at 90°C-rated insulation, what is the corrected ampacity?

• 95 amperes (no correction needed)
• 78 amperes
• 68 amperes
• 82 amperes

NEC Reference: NEC Table 310.16

Question 26: How is a surface extension made from a flush-mounted box?

• By attaching cable directly to the device
• By removing the box
• By taping the cable to the wall
• An extension ring secured over the box

NEC Reference: NEC 314.22

Question 27: Besides its control thermostat, what must each storage water heater have?

• A GFCI receptacle
• A pilot light
• A timer
• A temperature-limiting cutoff

NEC Reference: NEC 422.47

Question 28: How must the outlet supplying a self-contained spa or hot tub be protected?

• By AFCI
• By a GFCI
• No special protection is needed
• By a surge-protective device

NEC Reference: NEC 680.44

Question 29: How is a cord-and-plug-connected appliance (that must be grounded) connected to the equipment grounding conductor?

• Through the neutral conductor
• By a separate ground rod
• An EGC in the cord, grounding-type plug
• It does not need to be connected

NEC Reference: NEC 250.138(A)

Question 30: Type USE (underground service-entrance) cable is listed for use as:

• Underground service-entrance use
• Exposed wiring inside buildings
• Interior branch-circuit wiring
• Luminaire (fixture) wiring

NEC Reference: NEC 338.10