NABCEP Electrical & Mechanical Concepts

Question 1

What does DC stand for in solar PV systems?

Accepted Answer

Direct Current

Answer

In solar PV systems, DC stands for Direct Current. Solar panels generate electricity as direct current, meaning the electrical charge flows in only one direction. This DC power is then typically converted to Alternating Current (AC) by an inverter for use in homes and businesses or for feeding into the electrical grid.

Question 2

What converts DC to AC in a solar system?

Accepted Answer

Inverter

Answer

An inverter is the critical component in a solar PV system that converts the Direct Current (DC) electricity produced by the solar panels into Alternating Current (AC) electricity. AC power is the standard form of electricity used by most household appliances and the electrical grid, making the inverter essential for integrating solar power into a home or utility system.

Question 3

Which wire carries current back to the source?

Accepted Answer

Neutral wire

Answer

In an AC electrical system, the neutral wire provides the return path for current from the load back to the source, completing the circuit. While the hot wire carries the energized current to the load, the neutral wire maintains a voltage close to ground potential and is essential for the proper and safe operation of most electrical devices.

Question 4

What is the purpose of a circuit breaker?

Accepted Answer

Interrupts overcurrent

Answer

A circuit breaker is a safety device designed to automatically interrupt the flow of electricity when an overcurrent condition occurs, such as a short circuit or an overload. By tripping and opening the circuit, it protects electrical wiring, equipment, and personnel from damage or hazards caused by excessive current.

Question 5

What is Ohm’s Law?

Accepted Answer

R = V/C

Answer

Ohm's Law is a fundamental principle in electricity that describes the relationship between voltage (V), current (I), and resistance (R). The formula V = IR states that voltage equals current multiplied by resistance. Rearranging this formula to solve for resistance gives R = V/I. Therefore, if 'C' is used to denote current, then R = V/C correctly represents Ohm's Law for calculating resistance.

(NABCEP) North American Board of Certified Energy Practitioners Solar Practice Test

(NABCEP) North American Board of Certified Energy Practitioners Solar Practice Test

NABCEP Electrical & Mechanical Concepts