NECA Electrical Theory & Principles 2

Question 1

What happens to the total resistance when resistors are connected in parallel?

Accepted Answer

It is always less than the smallest resistor

Answer

In a parallel circuit, the total resistance is always less than the smallest individual resistor because current has multiple paths to flow through.

Question 2

Which law states that the algebraic sum of all currents entering and leaving a node equals zero?

Accepted Answer

Kirchhoff's Current Law

Answer

Kirchhoff's Current Law (KCL) states that the sum of currents entering a junction equals the sum of currents leaving it, based on conservation of charge.

Question 3

A capacitor in a DC circuit, after fully charging, acts as:

Accepted Answer

An open circuit

Answer

Once fully charged, a capacitor blocks DC current because no more current flows when the capacitor voltage equals the source voltage, effectively acting as an open circuit.

Question 4

What is the unit of magnetic flux density?

Accepted Answer

Tesla

Answer

Tesla (T) is the SI unit of magnetic flux density, defined as one weber per square meter (Wb/m²).

Question 5

In an AC circuit, when voltage and current are in phase, the power factor is:

Accepted Answer

1

Answer

A power factor of 1 (unity) occurs when voltage and current are perfectly in phase, meaning all power delivered is real (active) power with no reactive component.

(NECA) National Electrical Contractors Association Practice Test

(NECA) National Electrical Contractors Association Practice Test

NECA Electrical Theory & Principles 2