2AZ L-44 Solar Systems 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) solar panel?
a. To convert AC electricity into DC electricity
b. To convert sunlight directly into DC electrical energy
c. To store electricity for nighttime use
d. To regulate the frequency of utility power
Rationale: Photovoltaic cells convert sunlight into direct-current (DC)
electricity through the photovoltaic effect. The resulting electricity can
be used directly by compatible DC loads, converted to AC by an
inverter, or stored in batteries. Solar panels themselves do not store
electricity or directly produce standard household AC power.
,2. Which component converts the DC electricity produced by solar
panels into AC electricity for household use?
a. Charge controller
b. Combiner box
c. Inverter
d. Disconnect switch
Rationale: An inverter converts DC electricity from photovoltaic
modules or batteries into alternating-current (AC) electricity. Grid-
connected inverters synchronize their output with the utility supply,
while standalone inverters provide AC power to isolated loads. A
charge controller regulates battery charging, and disconnect switches
provide a means of isolating circuits.
3. What is the main purpose of a solar charge controller in an off-grid
photovoltaic system?
a. To increase the voltage of every solar module
b. To regulate battery charging and help prevent overcharging
c. To convert DC power into AC power
d. To synchronize the system with the utility grid
,Rationale: A charge controller regulates the electrical energy
delivered from the solar array to the battery bank. It helps maintain
appropriate charging conditions and protects batteries against
overcharging. Some controllers also provide low-voltage load-
disconnection functions. They do not replace the inverter or perform
utility synchronization.
4. Which solar panel orientation generally provides the greatest
annual solar energy production in Arizona?
a. Facing due north
b. Facing due east
c. Facing approximately due south
d. Facing due west
Rationale: In Arizona, which is in the Northern Hemisphere, a fixed
solar array facing approximately true south generally receives
favorable annual sunlight exposure. The ideal tilt and orientation
depend on latitude, seasonal energy needs, roof conditions, shading,
and system design. East- or west-facing arrays can still be effective,
particularly when electricity production is desired at specific times of
day.
5. What is the effect of shading on a photovoltaic module?
, a. It always increases the module's voltage
b. It has no effect if only one cell is shaded
c. It can reduce electrical output and may affect other cells connected
in series
d. It automatically increases the module's operating temperature to
improve efficiency
Rationale: Shading reduces the sunlight available to affected cells and
can significantly reduce module output. Because cells connected in
series share the same current path, a shaded cell can restrict current
through a larger portion of the circuit. Bypass diodes can reduce
certain shading-related losses, but they do not eliminate all shading
effects.
6. What does the term “photovoltaic effect” describe?
a. The storage of sunlight as heat in a water tank
b. The generation of electrical voltage when light interacts with a
suitable semiconductor
c. The conversion of AC electricity into mechanical energy
d. The reduction of electrical resistance caused by grounding
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A| Instant
Download Pdf
1. What is the primary function of a photovoltaic (PV) solar panel?
a. To convert AC electricity into DC electricity
b. To convert sunlight directly into DC electrical energy
c. To store electricity for nighttime use
d. To regulate the frequency of utility power
Rationale: Photovoltaic cells convert sunlight into direct-current (DC)
electricity through the photovoltaic effect. The resulting electricity can
be used directly by compatible DC loads, converted to AC by an
inverter, or stored in batteries. Solar panels themselves do not store
electricity or directly produce standard household AC power.
,2. Which component converts the DC electricity produced by solar
panels into AC electricity for household use?
a. Charge controller
b. Combiner box
c. Inverter
d. Disconnect switch
Rationale: An inverter converts DC electricity from photovoltaic
modules or batteries into alternating-current (AC) electricity. Grid-
connected inverters synchronize their output with the utility supply,
while standalone inverters provide AC power to isolated loads. A
charge controller regulates battery charging, and disconnect switches
provide a means of isolating circuits.
3. What is the main purpose of a solar charge controller in an off-grid
photovoltaic system?
a. To increase the voltage of every solar module
b. To regulate battery charging and help prevent overcharging
c. To convert DC power into AC power
d. To synchronize the system with the utility grid
,Rationale: A charge controller regulates the electrical energy
delivered from the solar array to the battery bank. It helps maintain
appropriate charging conditions and protects batteries against
overcharging. Some controllers also provide low-voltage load-
disconnection functions. They do not replace the inverter or perform
utility synchronization.
4. Which solar panel orientation generally provides the greatest
annual solar energy production in Arizona?
a. Facing due north
b. Facing due east
c. Facing approximately due south
d. Facing due west
Rationale: In Arizona, which is in the Northern Hemisphere, a fixed
solar array facing approximately true south generally receives
favorable annual sunlight exposure. The ideal tilt and orientation
depend on latitude, seasonal energy needs, roof conditions, shading,
and system design. East- or west-facing arrays can still be effective,
particularly when electricity production is desired at specific times of
day.
5. What is the effect of shading on a photovoltaic module?
, a. It always increases the module's voltage
b. It has no effect if only one cell is shaded
c. It can reduce electrical output and may affect other cells connected
in series
d. It automatically increases the module's operating temperature to
improve efficiency
Rationale: Shading reduces the sunlight available to affected cells and
can significantly reduce module output. Because cells connected in
series share the same current path, a shaded cell can restrict current
through a larger portion of the circuit. Bypass diodes can reduce
certain shading-related losses, but they do not eliminate all shading
effects.
6. What does the term “photovoltaic effect” describe?
a. The storage of sunlight as heat in a water tank
b. The generation of electrical voltage when light interacts with a
suitable semiconductor
c. The conversion of AC electricity into mechanical energy
d. The reduction of electrical resistance caused by grounding
