Designer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which component in a photovoltaic (PV) system converts sunlight
directly into electricity?
A. Inverter
B. Transformer
C. Battery bank
D. Solar module
The solar module contains photovoltaic cells that convert solar radiation
into direct current electricity through the photovoltaic effect.
2. What is the primary function of an inverter in a solar energy system?
,A. Store electrical energy
B. Increase panel temperature
C. Convert DC electricity to AC electricity
D. Ground the array
Most residential and commercial loads use alternating current, so the
inverter converts direct current generated by solar panels into usable
alternating current electricity.
3. Which factor most significantly affects the output of a solar PV
module?
A. Wind direction
B. Soil composition
C. Roof color
D. Solar irradiance
Solar irradiance measures the amount of sunlight striking the module
surface and directly impacts electrical generation.
4. Which type of solar panel generally has the highest efficiency?
A. Thin-film
B. Polycrystalline
C. Amorphous silicon
D. Monocrystalline
,Monocrystalline panels use single-crystal silicon, which allows better
electron flow and typically results in higher efficiencies.
5. What does STC stand for in photovoltaic testing?
A. Solar Thermal Conversion
B. System Transfer Calculation
C. Standard Test Conditions
D. Silicon Thermal Capacity
Standard Test Conditions are laboratory conditions used to rate PV module
performance at 1000 W/m² irradiance, 25°C cell temperature, and AM1.5
spectrum.
6. Which instrument is commonly used to measure solar irradiance on-
site?
A. Megohmmeter
B. Clamp meter
C. Pyranometer
D. Hydrometer
A pyranometer measures solar radiation received on a surface and is
essential for site assessment and performance analysis.
7. What is the purpose of maximum power point tracking (MPPT)?
, A. Reduce panel efficiency
B. Prevent grounding faults
C. Optimize power output from PV modules
D. Increase battery temperature
MPPT technology continuously adjusts operating voltage and current to
maximize energy harvested from the PV array.
8. Which roof orientation typically provides the greatest annual solar
production in Minnesota?
A. North-facing
B. East-facing
C. West-facing
D. South-facing
In the Northern Hemisphere, south-facing arrays generally receive the
highest annual solar exposure.
9. What is the unit used to measure electrical power?
A. Volt
B. Ampere
C. Ohm
D. Watt