Journeyman Electrician Practice
Test Questions and Answers
(Graded A)
Conductors with _____ marked on the insulation are NOT approved for use in
a wet location. - ANSWER-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? -
ANSWER-4/0 AWG
,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 _____. - ANSWER-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? - ANSWER-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.
, 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 _____ . - ANSWER-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
_____. - ANSWER-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. - ANSWER-10 ft.
Test Questions and Answers
(Graded A)
Conductors with _____ marked on the insulation are NOT approved for use in
a wet location. - ANSWER-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? -
ANSWER-4/0 AWG
,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 _____. - ANSWER-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? - ANSWER-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.
, 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 _____ . - ANSWER-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
_____. - ANSWER-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. - ANSWER-10 ft.
