IEC Final Exam Year 1
1. What is the result if the neutral wire becomes open on a.
a multiwire circuit having unequal loads? The load of higher resis-
a. tance would overheat and
The load of higher resistance would overheat and probably be damaged.
probably be damaged.
b.
The load of lesser resistance would overheat and prob-
ably be damaged.
c.
No effect until one load is turned off or opens.
d.
No effect.
2. Circuits 7 and 9 share a neutral. This is a multiwire 3 Amps
branch circuit. If Ckt. 7 is drawing 13 amps and Ckt. 9 is
drawing 16 amps, how much current is flowing in the
neutral?
a.3
b.13
c.29
d.16
3. The Code reference that specifies the type of discon- b. 240.15(B)(1)
necting means (circuit breaker for example) that can
be used on a multiwire branch circuit that feeds de-
vices mounted on the same yoke [a stack switch or a
duplex receptacle for example] is ___.Note: Select N/A
(not applicable) if there is not an NEC® requirement.
a.Article 100
b.240.15(B)(1)
, IEC Final Exam Year 1
c.404.8(A)
d.N/A
4. Voltmeters are connected in ___ with the load when Parallel
used to measure voltage across a load in a circuit.
5. The neutral has been removed from the neutral bar in Series
the circuit shown in Figure 128.407. Lamp 3 is connect- (3 wire parallel circuits
ed in ___ with Lamps 1 and 2. turn to series when the
neutral is disconnected
from the neutral bar)
6. What is the minimum number of receptacles required c. 1
in an unfinished basement?
a.2
b.4
c.1
d.0
7. The overall diameter (including insulation) of a 250 d. 711
kcmil THHN/THWN copper conductor is ___ inches?
NEC Chapter 9 Table 5 pg
a..082 701
b..397
c..765
d..711
e..575
8. What part of the NEC® is a reference for calculating c. Annex C
conduit fill where all conductors are the same size?
a.Article 100
, IEC Final Exam Year 1
b.Table 310.15(B)(16)
c.Annex C
d.Table 314.16(A)
9. What is the minimum trade size Schedule 80 PVC re- b. 3/4
quired to contain four 8 AWG THHN/THWN copper
conductors? NEC Annex C
a.1
b.3/4
c.11/4
d.11/2
e.none of these
10. Eleven #12, five #10, and six #6 THHN/THWN conduc- c. 11/4
tors will be installed in a run of EMT. The smallest trade
size EMT you can use is ___. NEC Chapter 9 Tables 4
and 5
a.11/2
b.21/2
c.11/4
d.2
e.1
11. A short length of EMT is run between two panels. The c. 24 inches
ampacity values for the conductors in this EMT need
not be derated, as long as the length of the EMT does
not exceed ___.
a.12 inches
b.18 inches
c.24 inches
1. What is the result if the neutral wire becomes open on a.
a multiwire circuit having unequal loads? The load of higher resis-
a. tance would overheat and
The load of higher resistance would overheat and probably be damaged.
probably be damaged.
b.
The load of lesser resistance would overheat and prob-
ably be damaged.
c.
No effect until one load is turned off or opens.
d.
No effect.
2. Circuits 7 and 9 share a neutral. This is a multiwire 3 Amps
branch circuit. If Ckt. 7 is drawing 13 amps and Ckt. 9 is
drawing 16 amps, how much current is flowing in the
neutral?
a.3
b.13
c.29
d.16
3. The Code reference that specifies the type of discon- b. 240.15(B)(1)
necting means (circuit breaker for example) that can
be used on a multiwire branch circuit that feeds de-
vices mounted on the same yoke [a stack switch or a
duplex receptacle for example] is ___.Note: Select N/A
(not applicable) if there is not an NEC® requirement.
a.Article 100
b.240.15(B)(1)
, IEC Final Exam Year 1
c.404.8(A)
d.N/A
4. Voltmeters are connected in ___ with the load when Parallel
used to measure voltage across a load in a circuit.
5. The neutral has been removed from the neutral bar in Series
the circuit shown in Figure 128.407. Lamp 3 is connect- (3 wire parallel circuits
ed in ___ with Lamps 1 and 2. turn to series when the
neutral is disconnected
from the neutral bar)
6. What is the minimum number of receptacles required c. 1
in an unfinished basement?
a.2
b.4
c.1
d.0
7. The overall diameter (including insulation) of a 250 d. 711
kcmil THHN/THWN copper conductor is ___ inches?
NEC Chapter 9 Table 5 pg
a..082 701
b..397
c..765
d..711
e..575
8. What part of the NEC® is a reference for calculating c. Annex C
conduit fill where all conductors are the same size?
a.Article 100
, IEC Final Exam Year 1
b.Table 310.15(B)(16)
c.Annex C
d.Table 314.16(A)
9. What is the minimum trade size Schedule 80 PVC re- b. 3/4
quired to contain four 8 AWG THHN/THWN copper
conductors? NEC Annex C
a.1
b.3/4
c.11/4
d.11/2
e.none of these
10. Eleven #12, five #10, and six #6 THHN/THWN conduc- c. 11/4
tors will be installed in a run of EMT. The smallest trade
size EMT you can use is ___. NEC Chapter 9 Tables 4
and 5
a.11/2
b.21/2
c.11/4
d.2
e.1
11. A short length of EMT is run between two panels. The c. 24 inches
ampacity values for the conductors in this EMT need
not be derated, as long as the length of the EMT does
not exceed ___.
a.12 inches
b.18 inches
c.24 inches
