AZ L-94 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 alternating current into direct current
b. Store electrical energy for nighttime use
c. Convert sunlight directly into direct-current (DC) electricity
d. Increase the frequency of electrical power
Rationale: Photovoltaic cells use semiconductor materials to convert
sunlight into DC electricity through the photovoltaic effect. The
modules generate electricity when exposed to light but do not
inherently store energy. Batteries or other storage systems are
required to retain energy for later use.
,2. Which semiconductor material is most commonly used in
conventional solar photovoltaic modules?
a. Copper
b. Aluminum
c. Silicon
d. Lead
Rationale: Silicon is widely used in PV cells because of its
semiconductor properties, availability, and established manufacturing
processes. When sunlight strikes the cell, photons can generate
electron-hole pairs, allowing electrical current to flow through an
external circuit.
3. What is the primary purpose of an inverter in a grid-connected solar
PV system?
a. Convert AC electricity into DC electricity for the utility grid
b. Store excess electricity in the PV modules
c. Convert DC electricity from the PV array into AC electricity
d. Increase the amount of sunlight reaching the modules
Rationale: PV modules produce DC electricity, while most buildings
and utility grids operate on AC electricity. The inverter converts the
,array's DC output into AC power and synchronizes it with the electrical
characteristics of the grid when operating in grid-connected mode.
4. What does the term “irradiance” mean in solar energy applications?
a. The total electricity generated during a year
b. The operating temperature of a solar module
c. The solar power received per unit area
d. The amount of energy stored in a battery
Rationale: Solar irradiance is the instantaneous power of solar
radiation received per unit area, commonly expressed in watts per
square meter (W/m²). Irradiance directly affects the current produced
by PV modules. It differs from irradiation, which describes solar
energy received over a period of time.
5. Which factor generally has the greatest direct effect on the current
output of a PV module?
a. The color of the mounting rails
b. The length of the grounding conductor
c. The intensity of sunlight reaching the cells
d. The brand of the junction box
, Rationale: PV cell current generally increases as incident irradiance
increases. Shading, cloud cover, dirt, and the orientation of the
module can reduce the sunlight reaching the cells and therefore
reduce current output. Temperature has a particularly significant
effect on voltage.
6. What happens to the open-circuit voltage of a typical silicon PV
module as its cell temperature increases?
a. It increases significantly
b. It remains exactly constant
c. It generally decreases
d. It becomes equal to zero immediately
Rationale: Silicon PV modules generally have a negative voltage
temperature coefficient. As cell temperature rises, the open-circuit
voltage decreases. This characteristic is important when calculating
maximum system voltage in cold conditions and estimating operating
performance in hot Arizona weather.
7. What is the purpose of the maximum power point tracking (MPPT)
function in an inverter?
a. Prevent all possible electrical faults
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 alternating current into direct current
b. Store electrical energy for nighttime use
c. Convert sunlight directly into direct-current (DC) electricity
d. Increase the frequency of electrical power
Rationale: Photovoltaic cells use semiconductor materials to convert
sunlight into DC electricity through the photovoltaic effect. The
modules generate electricity when exposed to light but do not
inherently store energy. Batteries or other storage systems are
required to retain energy for later use.
,2. Which semiconductor material is most commonly used in
conventional solar photovoltaic modules?
a. Copper
b. Aluminum
c. Silicon
d. Lead
Rationale: Silicon is widely used in PV cells because of its
semiconductor properties, availability, and established manufacturing
processes. When sunlight strikes the cell, photons can generate
electron-hole pairs, allowing electrical current to flow through an
external circuit.
3. What is the primary purpose of an inverter in a grid-connected solar
PV system?
a. Convert AC electricity into DC electricity for the utility grid
b. Store excess electricity in the PV modules
c. Convert DC electricity from the PV array into AC electricity
d. Increase the amount of sunlight reaching the modules
Rationale: PV modules produce DC electricity, while most buildings
and utility grids operate on AC electricity. The inverter converts the
,array's DC output into AC power and synchronizes it with the electrical
characteristics of the grid when operating in grid-connected mode.
4. What does the term “irradiance” mean in solar energy applications?
a. The total electricity generated during a year
b. The operating temperature of a solar module
c. The solar power received per unit area
d. The amount of energy stored in a battery
Rationale: Solar irradiance is the instantaneous power of solar
radiation received per unit area, commonly expressed in watts per
square meter (W/m²). Irradiance directly affects the current produced
by PV modules. It differs from irradiation, which describes solar
energy received over a period of time.
5. Which factor generally has the greatest direct effect on the current
output of a PV module?
a. The color of the mounting rails
b. The length of the grounding conductor
c. The intensity of sunlight reaching the cells
d. The brand of the junction box
, Rationale: PV cell current generally increases as incident irradiance
increases. Shading, cloud cover, dirt, and the orientation of the
module can reduce the sunlight reaching the cells and therefore
reduce current output. Temperature has a particularly significant
effect on voltage.
6. What happens to the open-circuit voltage of a typical silicon PV
module as its cell temperature increases?
a. It increases significantly
b. It remains exactly constant
c. It generally decreases
d. It becomes equal to zero immediately
Rationale: Silicon PV modules generally have a negative voltage
temperature coefficient. As cell temperature rises, the open-circuit
voltage decreases. This characteristic is important when calculating
maximum system voltage in cold conditions and estimating operating
performance in hot Arizona weather.
7. What is the purpose of the maximum power point tracking (MPPT)
function in an inverter?
a. Prevent all possible electrical faults
