Solar PV Practice Test: NABCEP PV Associate Fundamentals
Solar resource, modules and IV curves, system components, sizing math, design basics, safety and troubleshooting for the PV Associate exam and solar contractor licences.
173 questions · 7 topics · free, no sign-up
Mixed practice test
10 questions, graded as you go, with the reason for every answer. No sign-up.
Timed mock exam
50 questions in 60 minutes, drawn from every topic. No answers shown until the end, then a score, your weakest topics and a review of what you missed.
What does the maximum power point tracking (MPPT) function of an inverter do?
Adjusts the array's operating voltage to get the most power
Turns the array mechanically so that it faces the sun
Limits the array voltage on cold days to a safe value
Shuts the inverter down whenever the grid voltage has been lost
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A. Adjusts the array's operating voltage to get the most power
MPPT electronics continuously shift the array's operating point to the knee of the IV curve, which moves as irradiance and temperature change. Physically following the sun is done by a tracker, which is a mounting system rather than an inverter function.
Reference: Inverters: maximum power point tracking
Which conductor types are permitted for exposed single-conductor PV source circuit wiring run within the array outdoors?
THHN or THWN
NM cable or UF cable
XHHW or TW
PV wire or USE-2
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D. PV wire or USE-2
Exposed array wiring must stand up to sunlight, heat and moisture, so listed PV wire (PV cable) or sunlight-resistant USE-2 is used. THHN is a building wire meant for raceways and is not rated for exposed use on a roof.
Reference: NEC 2023, 690.31(C)(1)
A 24 V battery is connected to a 6 ohm resistive load. How much current flows?
144 A
4 A
0.25 A
30 A
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B. 4 A
Ohm's law gives current as voltage divided by resistance: 24 V ÷ 6 Ω = 4 A. Multiplying the two (144) is the common slip, and 0.25 comes from dividing resistance by voltage.
Reference: Ohm's law: I = E / R
About what open-circuit voltage does a single crystalline silicon cell produce, whatever its size?
1.5 to 2.0 V
5 to 6 V
0.5 to 0.7 V
12 to 14 V
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C. 0.5 to 0.7 V
A silicon cell produces roughly half a volt to a little over 0.6 V open circuit; the voltage is set by the material, not the cell area. That is why modules string dozens of cells in series to reach a useful voltage.
Reference: PV cell characteristics: cell voltage
Before a new string is connected to the inverter, which two checks should be made at its ends with a DC voltmeter?
Operating current and frequency
Power factor and frequency
Open-circuit voltage and polarity
Insulation thickness and polarity
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C. Open-circuit voltage and polarity
Measuring Voc confirms that the right number of modules are in series and connected, and checking polarity confirms positive and negative are not swapped. Connecting a reversed or over-voltage string can destroy equipment.