Iowa Solar Contractor Qualification
Advanced 100-Question Practice Exam
2026 | Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1.
A grid-connected rooftop PV system is being installed on a dwelling in Iowa.
Which NEC article is the primary article governing photovoltaic systems?
A. Article 680
B. Article 690
C. Article 695
D. Article 725
Answer: Article 690
Rationale: Article 690 specifically addresses photovoltaic systems, including PV
circuit requirements, wiring methods, disconnecting means, grounding, rapid
shutdown, and other system provisions.
,2.
Which NEC article is most directly applicable when a PV system is interconnected
with another source of electric power, such as a utility service?
A. Article 250
B. Article 300
C. Article 705
D. Article 720
Answer: Article 705
Rationale: Article 705 addresses interconnected electric power production
sources, including PV systems operating in parallel with another source.
3.
An installer is determining whether the PV array voltage remains within the
inverter's maximum DC input rating during the coldest expected conditions.
Which characteristic is most important?
A. Maximum operating temperature
B. Temperature-corrected open-circuit voltage
C. Short-circuit current at 25°C only
D. AC power factor
Answer: Temperature-corrected open-circuit voltage
Rationale: PV module open-circuit voltage increases as temperature decreases.
The maximum string voltage must be calculated using the applicable low-
temperature correction and compared with the equipment rating.
4.
A PV module has an open-circuit voltage of 49 V. Ten modules are connected in
series. Before temperature correction, what is the array open-circuit voltage?
,A. 4.9 V
B. 49 V
C. 490 V
D. 980 V
Answer: 490 V
Rationale: Series-connected modules add voltage. Ten modules × 49 V = 490 V.
5.
What happens to voltage when identical PV modules are connected in parallel?
A. Voltage is multiplied by the number of modules
B. Voltage remains approximately the same while current increases
C. Voltage becomes zero
D. Voltage decreases proportionally to the number of modules
Answer: Voltage remains approximately the same while current increases
Rationale: Parallel circuits maintain approximately the same voltage while the
available current from the parallel branches is additive.
6.
Three identical PV strings each have an Isc of 12 A and are connected in parallel.
Ignoring adjustment factors for the moment, what is the combined short-circuit
current?
A. 4 A
B. 12 A
C. 24 A
D. 36 A
Answer: 36 A
Rationale: Parallel current is additive. Three strings × 12 A = 36 A.
7.
, Why is the PV short-circuit current generally used rather than the maximum-
power current when establishing certain conductor and overcurrent
requirements?
A. Isc represents the highest normal current characteristic of the module
B. Imp always equals Isc
C. Isc is always lower than Imp
D. Isc is an AC measurement
Answer: Isc represents the highest normal current characteristic of the module
Rationale: PV current calculations use the manufacturer's short-circuit current as
the basis for several NEC sizing and protection calculations, subject to the
applicable code adjustment and correction factors.
8.
What is the principal purpose of a PV source-circuit overcurrent protective
device?
A. Increase module voltage
B. Protect conductors and equipment against excessive current
C. Improve inverter efficiency
D. Eliminate the need for disconnects
Answer: Protect conductors and equipment against excessive current
Rationale: Overcurrent protection limits fault current to a level that the
conductors and equipment can safely withstand.
9.
A PV string has a maximum circuit current of 11 A. If the applicable continuous-
current multiplier is 125%, what is the resulting calculated current?
A. 8.8 A
B. 11 A
Advanced 100-Question Practice Exam
2026 | Questions & Answers with
Detailed Rationales | Complete Exam
Prep & Study Guide
1.
A grid-connected rooftop PV system is being installed on a dwelling in Iowa.
Which NEC article is the primary article governing photovoltaic systems?
A. Article 680
B. Article 690
C. Article 695
D. Article 725
Answer: Article 690
Rationale: Article 690 specifically addresses photovoltaic systems, including PV
circuit requirements, wiring methods, disconnecting means, grounding, rapid
shutdown, and other system provisions.
,2.
Which NEC article is most directly applicable when a PV system is interconnected
with another source of electric power, such as a utility service?
A. Article 250
B. Article 300
C. Article 705
D. Article 720
Answer: Article 705
Rationale: Article 705 addresses interconnected electric power production
sources, including PV systems operating in parallel with another source.
3.
An installer is determining whether the PV array voltage remains within the
inverter's maximum DC input rating during the coldest expected conditions.
Which characteristic is most important?
A. Maximum operating temperature
B. Temperature-corrected open-circuit voltage
C. Short-circuit current at 25°C only
D. AC power factor
Answer: Temperature-corrected open-circuit voltage
Rationale: PV module open-circuit voltage increases as temperature decreases.
The maximum string voltage must be calculated using the applicable low-
temperature correction and compared with the equipment rating.
4.
A PV module has an open-circuit voltage of 49 V. Ten modules are connected in
series. Before temperature correction, what is the array open-circuit voltage?
,A. 4.9 V
B. 49 V
C. 490 V
D. 980 V
Answer: 490 V
Rationale: Series-connected modules add voltage. Ten modules × 49 V = 490 V.
5.
What happens to voltage when identical PV modules are connected in parallel?
A. Voltage is multiplied by the number of modules
B. Voltage remains approximately the same while current increases
C. Voltage becomes zero
D. Voltage decreases proportionally to the number of modules
Answer: Voltage remains approximately the same while current increases
Rationale: Parallel circuits maintain approximately the same voltage while the
available current from the parallel branches is additive.
6.
Three identical PV strings each have an Isc of 12 A and are connected in parallel.
Ignoring adjustment factors for the moment, what is the combined short-circuit
current?
A. 4 A
B. 12 A
C. 24 A
D. 36 A
Answer: 36 A
Rationale: Parallel current is additive. Three strings × 12 A = 36 A.
7.
, Why is the PV short-circuit current generally used rather than the maximum-
power current when establishing certain conductor and overcurrent
requirements?
A. Isc represents the highest normal current characteristic of the module
B. Imp always equals Isc
C. Isc is always lower than Imp
D. Isc is an AC measurement
Answer: Isc represents the highest normal current characteristic of the module
Rationale: PV current calculations use the manufacturer's short-circuit current as
the basis for several NEC sizing and protection calculations, subject to the
applicable code adjustment and correction factors.
8.
What is the principal purpose of a PV source-circuit overcurrent protective
device?
A. Increase module voltage
B. Protect conductors and equipment against excessive current
C. Improve inverter efficiency
D. Eliminate the need for disconnects
Answer: Protect conductors and equipment against excessive current
Rationale: Overcurrent protection limits fault current to a level that the
conductors and equipment can safely withstand.
9.
A PV string has a maximum circuit current of 11 A. If the applicable continuous-
current multiplier is 125%, what is the resulting calculated current?
A. 8.8 A
B. 11 A
