CO Solar Photovoltaic Contractor Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
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1. What is the primary function of a photovoltaic (PV) module?
A. Convert AC electricity into DC electricity
B. Store electrical energy for later use
C. Convert sunlight directly into DC electrical energy
D. Increase the utility grid frequency
Answer: C. Convert sunlight directly into DC electrical energy
Rationale: PV modules use semiconductor cells to convert incident
sunlight into direct-current (DC) electrical energy through the
photovoltaic effect. The module itself does not normally store energy
or produce alternating current (AC); an inverter is used to convert DC
power to AC.
, 2. Which component converts the DC output of a PV array into AC
electricity suitable for typical building loads?
A. Combiner box
B. Inverter
C. Disconnect switch
D. Charge controller
Answer: B. Inverter
Rationale: A grid-connected PV inverter converts the DC electricity
produced by the PV array into synchronized AC electricity. It also
performs functions such as voltage regulation, maximum-power-point
tracking, and grid protection, depending on the equipment and
system design.
3. What happens to the current from identical PV modules
connected in series?
A. It adds together
B. It remains approximately the same as the current of one module
C. It becomes zero
D. It doubles regardless of module rating
Answer: B. It remains approximately the same as the current of one
module
,Rationale: In a series circuit, the same current flows through each
component. Therefore, the string current is approximately equal to
the current of the individual module, while the module voltages add
together.
4. What happens to voltage when identical PV modules are
connected in parallel?
A. Their voltages add together
B. The voltage becomes zero
C. The voltage remains approximately the same while current increases
D. The voltage always doubles
Answer: C. The voltage remains approximately the same while current
increases
Rationale: Parallel-connected sources operate at approximately the
same voltage, while their available currents add. This allows a PV
designer to increase array current without proportionally increasing
operating voltage.
5. Which condition generally causes a PV module to produce less
power?
A. Increased sunlight with ideal operating temperature
B. Partial shading
, C. Clean module surfaces
D. Proper orientation
Answer: B. Partial shading
Rationale: Shading reduces the amount of irradiance reaching PV cells
and can significantly reduce string output. Because modules are
electrically interconnected, shading on one portion of an array can
have effects beyond the shaded cells, depending on the system
configuration and bypass-diode arrangement.
6. What is the purpose of bypass diodes in many PV modules?
A. Increase utility voltage
B. Prevent all current from flowing through the module
C. Provide an alternate current path around shaded or damaged cell
sections
D. Convert DC to AC
Answer: C. Provide an alternate current path around shaded or
damaged cell sections
Rationale: Bypass diodes provide alternate current paths around
portions of a module when those portions become highly resistive,
such as during shading. This helps limit hot-spot formation and
reduces the impact of shading on module operation.
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary function of a photovoltaic (PV) module?
A. Convert AC electricity into DC electricity
B. Store electrical energy for later use
C. Convert sunlight directly into DC electrical energy
D. Increase the utility grid frequency
Answer: C. Convert sunlight directly into DC electrical energy
Rationale: PV modules use semiconductor cells to convert incident
sunlight into direct-current (DC) electrical energy through the
photovoltaic effect. The module itself does not normally store energy
or produce alternating current (AC); an inverter is used to convert DC
power to AC.
, 2. Which component converts the DC output of a PV array into AC
electricity suitable for typical building loads?
A. Combiner box
B. Inverter
C. Disconnect switch
D. Charge controller
Answer: B. Inverter
Rationale: A grid-connected PV inverter converts the DC electricity
produced by the PV array into synchronized AC electricity. It also
performs functions such as voltage regulation, maximum-power-point
tracking, and grid protection, depending on the equipment and
system design.
3. What happens to the current from identical PV modules
connected in series?
A. It adds together
B. It remains approximately the same as the current of one module
C. It becomes zero
D. It doubles regardless of module rating
Answer: B. It remains approximately the same as the current of one
module
,Rationale: In a series circuit, the same current flows through each
component. Therefore, the string current is approximately equal to
the current of the individual module, while the module voltages add
together.
4. What happens to voltage when identical PV modules are
connected in parallel?
A. Their voltages add together
B. The voltage becomes zero
C. The voltage remains approximately the same while current increases
D. The voltage always doubles
Answer: C. The voltage remains approximately the same while current
increases
Rationale: Parallel-connected sources operate at approximately the
same voltage, while their available currents add. This allows a PV
designer to increase array current without proportionally increasing
operating voltage.
5. Which condition generally causes a PV module to produce less
power?
A. Increased sunlight with ideal operating temperature
B. Partial shading
, C. Clean module surfaces
D. Proper orientation
Answer: B. Partial shading
Rationale: Shading reduces the amount of irradiance reaching PV cells
and can significantly reduce string output. Because modules are
electrically interconnected, shading on one portion of an array can
have effects beyond the shaded cells, depending on the system
configuration and bypass-diode arrangement.
6. What is the purpose of bypass diodes in many PV modules?
A. Increase utility voltage
B. Prevent all current from flowing through the module
C. Provide an alternate current path around shaded or damaged cell
sections
D. Convert DC to AC
Answer: C. Provide an alternate current path around shaded or
damaged cell sections
Rationale: Bypass diodes provide alternate current paths around
portions of a module when those portions become highly resistive,
such as during shading. This helps limit hot-spot formation and
reduces the impact of shading on module operation.
