NABCEP PV Associate (PVA) — Practice Exam
O&M: performance: practice questions
Our NABCEP PV Associate bank has 8 questions on this topic. Here are 3 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
On a hot summer afternoon, why might an array produce less power than on a cool, clear spring day with the same sunlight?
- Sunlight is much weaker in summer because the sun is farther from the earth
- Inverters work better in heat
- Higher cell temperature lowers voltage and power
- Heat raises current too much
Show the answer
C. Higher cell temperature lowers voltage and power — Power coefficient is about −0.4% to −0.5% per °C.
Question 2
A 12 V lead-acid battery reads 12.0 V at rest. What does this suggest?
- It is significantly discharged
- It is overcharged
- It has a shorted cell only if it reads 12.7 V
- It is fully charged
Show the answer
A. It is significantly discharged — A rested, fully charged 12 V lead-acid battery reads about 12.6–12.7 V.
Question 3
What happens if an array's Vmp falls below the inverter's MPPT range?
- The inverter can't track the maximum power point, reducing output or stopping it
- The array voltage doubles
- Nothing changes, because the inverter can boost any voltage
- The inverter produces more power
Show the answer
A. The inverter can't track the maximum power point, reducing output or stopping it — Check string length against hot-weather Vmp.