NHIE Electrical Systems 3 — Questions and Answers
Question 1: Which wire color is used for the ungrounded (hot) conductor in standard US residential 120V wiring?
- White
- Green
- Black (Correct answer)
- Gray
Correct answer: Black
Black is the standard color for the ungrounded (hot) conductor in 120V residential circuits.
Question 2: A home inspector observes a 240V dryer circuit using a 3-wire connection to a newer dryer. What is the issue?
- Dryers require 4-wire connections in new installations per current NEC (Correct answer)
- 3-wire connections are only for 120V circuits
- The dryer requires a dedicated 30-amp circuit, not a standard circuit
- 240V circuits always require conduit, not cable
Correct answer: Dryers require 4-wire connections in new installations per current NEC
Current NEC requires 4-wire connections (two hots, neutral, and ground) for new dryer installations to separate the neutral and ground.
Question 3: What is the standard amperage rating for a residential kitchen small appliance circuit?
- 15 amps
- 20 amps (Correct answer)
- 30 amps
- 40 amps
Correct answer: 20 amps
NEC requires at least two 20-amp small appliance circuits for kitchen countertop receptacles.
Question 4: An inspector finds a subpanel in a detached garage where the neutral and ground bars are bonded together. What should be reported?
- This is correct because all panels must bond neutral and ground
- This is a defect; subpanels must have separate neutral and ground bars (Correct answer)
- This is acceptable only if the garage has no equipment grounds
- Bonding is required only when the subpanel is fed by aluminum conductors
Correct answer: This is a defect; subpanels must have separate neutral and ground bars
In subpanels, the neutral and ground must be separated; bonding is only done at the main service panel.
Question 5: What type of protection is required for receptacles in a bathroom, within 6 feet of a sink?
- AFCI protection
- GFCI protection (Correct answer)
- Tamper-resistant receptacles
- Surge-protected receptacles
Correct answer: GFCI protection
GFCI protection is required for all bathroom receptacles due to the presence of water.
Question 6: A home inspector observes wiring connections made with wire nuts inside a wall without a junction box. What should be reported?
- Wire nuts are only permitted inside panels, not in walls
- All wiring splices must be made inside an accessible, covered junction box (Correct answer)
- Wire nuts require a minimum 6-inch tail for proper installation
- This is acceptable if the connections are within 12 inches of a stud
Correct answer: All wiring splices must be made inside an accessible, covered junction box
NEC requires all wiring splices to be enclosed in accessible junction boxes with proper covers.
Question 7: Which of the following is NOT a required location for AFCI protection in newer construction under current NEC?
- Bedroom circuits
- Kitchen circuits
- Bathroom circuits (Correct answer)
- Living room circuits
Correct answer: Bathroom circuits
Bathroom circuits require GFCI protection, not AFCI; AFCI is required for bedrooms, kitchens, living rooms, and most habitable spaces.
NHIE Electrical Systems 3
Which wire color is used for the ungrounded (hot) conductor in standard US residential 120V wiring?