JOURNEYMAN ELECTRICIAN
PRACTICE TEST QUESTIONS AND
ANSWERS
one-family dwelling 120/240 volt, single-phase, service-entrance conductors to be sized at an
ampacity of not less than 83% of the service rating. Therefore, 200 amperes x 83% = 166 amperes;
size 4/0 AWG THW aluminum conductors with an allowable ampacity of 180 amperes should be
selected for this dwelling.
Where a 150 kVA, single-phase transformer having a secondary voltage of 120/240 is installed at a
multi-family dwelling, the full-load current rating, in amperes, of the secondary is _____.
✅✅correct answ-625 amperes
To find the full-load current rating of the single-phase transformer apply the single-phase current
formula as shown:I = (150 kVA x 1000) / 240 volts = 15,000/240 = 625 amperes
Which one of the following listed circuit breakers is NOT a standard ampere rating? ✅✅correct
answ-75 amperes
the standard ampere ratings for fuses and circuit breakers. A circuit breaker with an ampere rating
of 75 amperes is not a standard ampere rating.
Conductors with _____ marked on the insulation are NOT approved for use in a wet location.
✅✅correct answ-THHN
conductors with THHN insulation are approved for use in dry and damp locations only and
conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations.
Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240
volt, single-phase, electrical system from the local utility company. What is the MINIMUM size
aluminum THW conductors required for use as service-entrance conductors for this residence?
✅✅correct answ-4/0 AWG
The MINIMUM length of free conductor to be left at each junction box for the purpose of splicing
conductors, or making connections to illuminares or devices shall be _____ . ✅✅correct answ-6
inches
, free conductor is to be left at each junction box for splices or the connection of luminaires or
devices. The intent of this rule is to ensure enough conductor slack for the terminal connections or
splices to be made easily.
In general, overhead service-drop conductors shall NOT be smaller than _____. ✅✅correct answ-
8 AWG copper
overhead service-drop conductors to be not smaller than 8 AWG copper or 6 AWG aluminum or
copper-clad aluminum. Do not get service-drop conductors, the overhead conductors between the
utility electric supply system and the service point, confused with the service-entrance conductors,
the conductors from the service point from the utility company to the service disconnecting means.
When a galvanized eye-bolt is to be used as the point of attachment for an electrical service, the NEC
requires the eye-bolt to be installed NOT less than _____ above finished grade. ✅✅correct answ-
10 ft.
provide adequate vertical clearance of the conductors and prevent physical damage to the
conductors and prevent persons from making accidental contact with the conductors which may
create a shock hazard or electrocution. In no case shall the point of attachment of the service-drop
conductors to be less than 10 ft. above finished grade.
Why is electrical continuity required for metallic conduit? ✅✅correct answ-To establish an
effective ground-fault path and facilitate the operation of the over-current protective device.
Electrical continuity is required for metallic conduit to establish an effective ground-fault path and
facilitate the operation of the overcurrent protective device.
In dwelling units, receptacle outlets installed for countertop surfaces, must be located above, but
NOT more than _____ above the countertop or work surface. ✅✅correct answ-20 inches
receptacle outlets installed for countertop or work surfaces in dwelling units may be located on or
above, but not more than 20 in. above the countertop or work surface. The intent of this rule is to
eliminate the use of unsightly extension cords (which reduces the amount of usable countertop
space) on the countertop or work surface to supply cord-and-plug connected appliances. Also,
receptacles located more than 20 inches above countertops or work surfaces may interfere with the
cabinetry to be installed.
PRACTICE TEST QUESTIONS AND
ANSWERS
one-family dwelling 120/240 volt, single-phase, service-entrance conductors to be sized at an
ampacity of not less than 83% of the service rating. Therefore, 200 amperes x 83% = 166 amperes;
size 4/0 AWG THW aluminum conductors with an allowable ampacity of 180 amperes should be
selected for this dwelling.
Where a 150 kVA, single-phase transformer having a secondary voltage of 120/240 is installed at a
multi-family dwelling, the full-load current rating, in amperes, of the secondary is _____.
✅✅correct answ-625 amperes
To find the full-load current rating of the single-phase transformer apply the single-phase current
formula as shown:I = (150 kVA x 1000) / 240 volts = 15,000/240 = 625 amperes
Which one of the following listed circuit breakers is NOT a standard ampere rating? ✅✅correct
answ-75 amperes
the standard ampere ratings for fuses and circuit breakers. A circuit breaker with an ampere rating
of 75 amperes is not a standard ampere rating.
Conductors with _____ marked on the insulation are NOT approved for use in a wet location.
✅✅correct answ-THHN
conductors with THHN insulation are approved for use in dry and damp locations only and
conductors with THWN, THHW, and THW insulation are recognized for use in dry and wet locations.
Given: A one-family dwelling unit with a demand load of 200 amperes is supplied with a 120/240
volt, single-phase, electrical system from the local utility company. What is the MINIMUM size
aluminum THW conductors required for use as service-entrance conductors for this residence?
✅✅correct answ-4/0 AWG
The MINIMUM length of free conductor to be left at each junction box for the purpose of splicing
conductors, or making connections to illuminares or devices shall be _____ . ✅✅correct answ-6
inches
, free conductor is to be left at each junction box for splices or the connection of luminaires or
devices. The intent of this rule is to ensure enough conductor slack for the terminal connections or
splices to be made easily.
In general, overhead service-drop conductors shall NOT be smaller than _____. ✅✅correct answ-
8 AWG copper
overhead service-drop conductors to be not smaller than 8 AWG copper or 6 AWG aluminum or
copper-clad aluminum. Do not get service-drop conductors, the overhead conductors between the
utility electric supply system and the service point, confused with the service-entrance conductors,
the conductors from the service point from the utility company to the service disconnecting means.
When a galvanized eye-bolt is to be used as the point of attachment for an electrical service, the NEC
requires the eye-bolt to be installed NOT less than _____ above finished grade. ✅✅correct answ-
10 ft.
provide adequate vertical clearance of the conductors and prevent physical damage to the
conductors and prevent persons from making accidental contact with the conductors which may
create a shock hazard or electrocution. In no case shall the point of attachment of the service-drop
conductors to be less than 10 ft. above finished grade.
Why is electrical continuity required for metallic conduit? ✅✅correct answ-To establish an
effective ground-fault path and facilitate the operation of the over-current protective device.
Electrical continuity is required for metallic conduit to establish an effective ground-fault path and
facilitate the operation of the overcurrent protective device.
In dwelling units, receptacle outlets installed for countertop surfaces, must be located above, but
NOT more than _____ above the countertop or work surface. ✅✅correct answ-20 inches
receptacle outlets installed for countertop or work surfaces in dwelling units may be located on or
above, but not more than 20 in. above the countertop or work surface. The intent of this rule is to
eliminate the use of unsightly extension cords (which reduces the amount of usable countertop
space) on the countertop or work surface to supply cord-and-plug connected appliances. Also,
receptacles located more than 20 inches above countertops or work surfaces may interfere with the
cabinetry to be installed.
