NJATC Residential Wiring

Question 1

In National Joint Apprenticeship and Training Committee, what is Ohm's Law?

Accepted Answer

V = I × R (Voltage equals Current times Resistance)

Answer

Ohm's Law states that voltage (V) equals current (I) multiplied by resistance (R). This fundamental relationship is essential for calculating electrical values in any circuit.

Question 2

What is the purpose of a circuit breaker in National Joint Apprenticeship and Training Committee residential wiring?

Accepted Answer

To automatically interrupt electrical flow when current exceeds safe levels

Answer

Circuit breakers are safety devices that automatically disconnect the circuit when current exceeds rated levels, protecting wiring and equipment from overload damage and reducing fire risk.

Question 3

In National Joint Apprenticeship and Training Committee, what is the difference between series and parallel circuits?

Accepted Answer

Series: components share one path; Parallel: components have separate paths

Answer

In a series circuit, components are connected in a single path so the same current flows through each. In parallel circuits, components have separate paths, sharing the same voltage but dividing the current.

Question 4

What does "grounding" mean in National Joint Apprenticeship and Training Committee electrical systems?

Accepted Answer

Providing a safe path for fault current to flow to earth, preventing electrical shock

Answer

Grounding creates a low-resistance path for fault current to flow safely to earth, protecting people from electrical shock and allowing protective devices to quickly disconnect faulted circuits.

Question 5

In National Joint Apprenticeship and Training Committee, what is alternating current (AC)?

Accepted Answer

Electrical current that periodically reverses direction

Answer

Alternating current (AC) periodically reverses direction, typically at 60 Hz (US) or 50 Hz (other countries). AC is used for power distribution because it can be efficiently transformed to different voltage levels.

NJATC - National Joint Apprenticeship and Training Committee Practice Test

NJATC - National Joint Apprenticeship and Training Committee Practice Test

NJATC Residential Wiring