IEC TEST BANK 2026 QUESTIONS WITH
SOLUTIONS GRADED A+
◉ A metal enclosure surrounding electrically operated equipment ___.
a. is required to be grounded
b. protects the equipment from physical damage
c. provides protection for people against accidental contact with live
parts. Answer: d. all of these
◉ The amount of current that flows in any circuit is determined by the
voltage and resistance of the circuit.
Select one:
a. True
b. False. Answer: a. True
◉ ___ is defined as case or housing of apparatus, or the fence or walls
surrounding an installation to prevent personnel from accidentally
contacting energized parts or to protect the equipment from physical
damage.
Select one:
a. Inaccessible
,b. Guarded
c. Isolated
d. Enclosure. Answer: : Enclosure
◉ The circuit installed in a run of PVC conduit requires a 6 AWG
equipment grounding conductor. However, a 12 AWG was installed
instead. Using the 12 instead of the 6 AWG wire will ___ the amount of
time required for a circuit breaker to open when a ground fault occurs.
Select one:
a. increase
b. decrease
c. have no effect on. Answer: increase
◉ Providing a low impedance ground return path ___ when a ground-
fault occurs.
Select one:
a. has no effect on the circuit current
b. permits a high current to flow
c. limits the amount of current to a small amount. Answer: permits a
high current to flow
◉ In a run of conduit, when couplings and connectors are loose this will
___ the amount of time required for a circuit breaker to open when a
short-circuit occurs.
,Select one:
a. have no effect on
b. increase
c. decrease. Answer: have no effect on
◉ The plans indicate that you should install a 300-amp branch circuit in
Schedule 40 PVC with a 4 AWG equipment grounding conductor.
However, you did not have any 4 AWG wire so you pulled in 10 AWG
instead. With a load connected, the normal circuit current will be ___
with the 10 AWG EGC (compared to using a 4 AWG EGC).
Select one:
a. the same
b. less
c. greater. Answer: the same
◉ The primary purpose of grounding metal equipment enclosures and
metal raceways to the grounding electrode system (earth) is to ___.I.
cause the quick operation of OCPDsII. keep all metal parts at the same
voltageIII. limit voltage surges
Select one:
a. I only
b. I, II & III
c. I & III only
d. I & II only
, e. II & III only. Answer: II & III only
◉ A metal enclosure surrounding electrically operated equipment ___.
Select one:
a. is required to be grounded
b. protects the equipment from physical damage
c. provides protection for people against accidental contact with live
parts
d. all of these. Answer: all of these
◉ Refer to Figure 205.15. The flex used between the breaker enclosure
and the motor contains three 350 kcmil conductors. The minimum size
of the EGC between the 700-A breaker and the motor is ___.
Select one:
a. 350 kcmil
b. 3/0 AWG
c. 2 AWG
d. 1/0 AWG
e. none of these. Answer: 1/0 AWG
◉ Three 4/0 AWG conductors are installed in the flex between the
breaker enclosure, containing a 500-A breaker, and the motor. The
smallest EGC that can be installed in the flex shown in Figure 205.15 is
___.
SOLUTIONS GRADED A+
◉ A metal enclosure surrounding electrically operated equipment ___.
a. is required to be grounded
b. protects the equipment from physical damage
c. provides protection for people against accidental contact with live
parts. Answer: d. all of these
◉ The amount of current that flows in any circuit is determined by the
voltage and resistance of the circuit.
Select one:
a. True
b. False. Answer: a. True
◉ ___ is defined as case or housing of apparatus, or the fence or walls
surrounding an installation to prevent personnel from accidentally
contacting energized parts or to protect the equipment from physical
damage.
Select one:
a. Inaccessible
,b. Guarded
c. Isolated
d. Enclosure. Answer: : Enclosure
◉ The circuit installed in a run of PVC conduit requires a 6 AWG
equipment grounding conductor. However, a 12 AWG was installed
instead. Using the 12 instead of the 6 AWG wire will ___ the amount of
time required for a circuit breaker to open when a ground fault occurs.
Select one:
a. increase
b. decrease
c. have no effect on. Answer: increase
◉ Providing a low impedance ground return path ___ when a ground-
fault occurs.
Select one:
a. has no effect on the circuit current
b. permits a high current to flow
c. limits the amount of current to a small amount. Answer: permits a
high current to flow
◉ In a run of conduit, when couplings and connectors are loose this will
___ the amount of time required for a circuit breaker to open when a
short-circuit occurs.
,Select one:
a. have no effect on
b. increase
c. decrease. Answer: have no effect on
◉ The plans indicate that you should install a 300-amp branch circuit in
Schedule 40 PVC with a 4 AWG equipment grounding conductor.
However, you did not have any 4 AWG wire so you pulled in 10 AWG
instead. With a load connected, the normal circuit current will be ___
with the 10 AWG EGC (compared to using a 4 AWG EGC).
Select one:
a. the same
b. less
c. greater. Answer: the same
◉ The primary purpose of grounding metal equipment enclosures and
metal raceways to the grounding electrode system (earth) is to ___.I.
cause the quick operation of OCPDsII. keep all metal parts at the same
voltageIII. limit voltage surges
Select one:
a. I only
b. I, II & III
c. I & III only
d. I & II only
, e. II & III only. Answer: II & III only
◉ A metal enclosure surrounding electrically operated equipment ___.
Select one:
a. is required to be grounded
b. protects the equipment from physical damage
c. provides protection for people against accidental contact with live
parts
d. all of these. Answer: all of these
◉ Refer to Figure 205.15. The flex used between the breaker enclosure
and the motor contains three 350 kcmil conductors. The minimum size
of the EGC between the 700-A breaker and the motor is ___.
Select one:
a. 350 kcmil
b. 3/0 AWG
c. 2 AWG
d. 1/0 AWG
e. none of these. Answer: 1/0 AWG
◉ Three 4/0 AWG conductors are installed in the flex between the
breaker enclosure, containing a 500-A breaker, and the motor. The
smallest EGC that can be installed in the flex shown in Figure 205.15 is
___.
