Delaware Solar Electrical Contractor
Qualification Practice Exam 2026 | 100+
Questions & Answers with Detailed
Rationales | Complete Delaware Solar
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1. What is the primary purpose of a photovoltaic (PV) system inverter?
A. Store electrical energy
B. Convert DC electricity to AC electricity
C. Increase panel voltage
D. Ground the PV array
Answer: Convert DC electricity to AC electricity
Rationale: The inverter converts the direct current produced by PV modules into
alternating current suitable for building loads and, when permitted,
interconnection with the utility system.
, 2. Which electrical code is the primary reference for photovoltaic system
installations?
A. NFPA 10
B. NEC Article 690
C. NEC Article 250 only
D. NFPA 101
Answer: NEC Article 690
Rationale: NEC Article 690 contains requirements specifically addressing
photovoltaic electrical systems, including circuits, wiring, overcurrent protection,
grounding, and equipment.
3. What is the function of a PV module?
A. Convert AC to DC
B. Convert sunlight into electrical energy
C. Store electrical energy
D. Regulate utility frequency
Answer: Convert sunlight into electrical energy
Rationale: Photovoltaic cells use the photovoltaic effect to convert solar
radiation into DC electrical energy.
4. What type of current is normally produced by a photovoltaic module?
A. AC
B. DC
C. Three-phase AC
D. Pulsed AC
Answer: DC
Rationale: PV modules produce direct current, which is subsequently converted
to AC by an inverter when required.
, 5. When PV modules are connected in series, what primarily increases?
A. Current
B. Voltage
C. Frequency
D. Power factor
Answer: Voltage
Rationale: Connecting PV modules in series adds their voltages while the current
remains approximately equal to the current of the individual modules.
6. When PV modules are connected in parallel, what primarily increases?
A. Voltage
B. Frequency
C. Current
D. Resistance
Answer: Current
Rationale: Parallel-connected PV circuits maintain approximately the same
voltage while their current capacities add together.
7. What is the purpose of a PV combiner box?
A. Convert AC to DC
B. Combine multiple PV source circuits
C. Store energy
D. Measure roof temperature
Answer: Combine multiple PV source circuits
Rationale: A combiner box combines multiple PV source circuits into one or more
output circuits and may contain overcurrent protection and other equipment.
8. What does an inverter's maximum power point tracking (MPPT) function
do?
, A. Disconnects the utility
B. Optimizes operation of the PV array at its maximum power point
C. Grounds the array
D. Converts AC to DC
Answer: Optimizes operation of the PV array at its maximum power point
Rationale: MPPT continuously adjusts operating conditions to extract maximum
available power from the PV array as irradiance and temperature change.
9. What is the purpose of overcurrent protection in a PV system?
A. Increase solar production
B. Protect conductors and equipment from excessive current
C. Improve panel appearance
D. Increase system frequency
Answer: Protect conductors and equipment from excessive current
Rationale: Overcurrent protection limits current to levels that protect
conductors, equipment, and associated electrical components from damage.
10.What is a PV source circuit?
A. The circuit between the utility and meter
B. The circuit formed by interconnected PV modules
C. The AC circuit serving building loads
D. The grounding electrode conductor
Answer: The circuit formed by interconnected PV modules
Rationale: A PV source circuit consists of conductors connected between PV
modules and the circuit or equipment where the source circuits are combined.
11.What is a PV output circuit?
A. The circuit between a PV source circuit and the inverter or other conversion
equipment