Electrical — NHIE Practice Questions

132 questions in this content area. 15 are published in full below with worked explanations.

1. A bathroom exhaust fan is wired to the light switch with no separate control. How should this be reported?

AAs a defect requiring rewiring immediately
As an arrangement, noting the fan runs only with the light
CAs evidence the circuit is overloaded
DAs a condition outside the inspection scope

Why B is correct

Why this is correct: The governing concept is functional arrangement versus code defect. Wiring a bathroom fan to the light switch is a common and code-compliant practice. It is not a defect, but it has a functional consequence (fan runs only with light) that the client should be aware of for moisture management. Why the other choices are wrong: As a defect requiring rewiring immediately is incorrect because the arrangement is typically code-compliant. As evidence the circuit is overloaded is wrong; shared switching does not inherently indicate overload. As a condition outside the inspection scope is false; installed systems and their operation are within scope. Exam tip: Distinguish between 'not ideal' and 'defective.' Report functional limitations so the client can make informed decisions.

2. A receptacle beside a bathroom sink has no cover plate and the device is loose in the box. Why is this reported?

The condition allows contact with energised terminals
BThe receptacle will not accept a three-prong plug
CLoose devices increase the circuit's resistance
DCover plates are required for appearance only

Why A is correct

Why this is correct: In a bathroom (a wet location), a missing cover plate and a loose receptacle expose energized terminals. This creates a severe shock hazard, as wet hands and damp surroundings significantly increase the risk of electrocution. The combination of accessibility and location makes this critical. Why the other choices are wrong: While a loose connection can increase resistance, the immediate hazard is contact with live parts. The inability to accept a three-prong plug is a separate issue. Cover plates are required for safety, not just appearance. Exam tip: Missing cover + loose device in a bathroom = high-risk shock hazard due to wet conditions.

3. A receptacle that holds a plug loosely, allowing it to fall partly out:

AImproves the ease of unplugging appliances
BIs a cosmetic issue with no safety aspect
CIndicates the plug is the wrong type
Has worn contacts that can arc and overheat

Why D is correct

Why this is correct: A loose plug has reduced contact area between the receptacle's contacts and the plug's prongs. This creates high electrical resistance at the point of connection, which generates heat and can lead to arcing, melting, and fire. Why the other choices are wrong: 'Improves the ease of unplugging appliances' is incorrect; a proper receptacle should hold a plug securely. 'Is a cosmetic issue with no safety aspect' is dangerously false; overheating and arcing are fire hazards. 'Indicates the plug is the wrong type' is unlikely; standard NEMA 5-15 plugs are universal for 15A receptacles. Wear is the typical cause. Exam tip: Loose plug = overheating hazard. This is a standard safety finding, not a minor annoyance.

4. A receptacle that reads 'open ground' on a tester in a house with modern wiring most likely indicates:

AThe circuit is overloaded at the panel
BThe receptacle has failed internally
A grounding conductor disconnected at some point
DThe tester is incompatible with modern receptacles

Why C is correct

Why this is correct: In a home with modern wiring (3-wire with ground), an 'open ground' reading means the grounding conductor's path back to the panel is broken or disconnected at some point—at the receptacle, in a junction box, or at the panel. The ground is not functional. Why the other choices are wrong: 'The circuit is overloaded at the panel' would trip the breaker, not cause an open ground reading. 'The receptacle has failed internally' is possible but less common than a simple disconnected wire. 'The tester is incompatible with modern receptacles' is unlikely; testers are designed for standard receptacles. Exam tip: Context matters. 'Open ground' in an old 2-wire house means no ground exists (expected). In a modern house, it means a ground is present but disconnected (a defect).

5. Cloth-insulated wiring with brittle, crumbling insulation at the panel indicates:

ADamage caused during the last panel service
BA wiring type that is inherently unsafe when new
Aged conductors needing electrician evaluation
DNormal appearance requiring no comment

Why C is correct

Why this is correct: Aged conductors needing electrician evaluation. Cloth-insulated wiring is old, and the insulation becomes brittle and crumbles with age and heat exposure, especially at points of bending like panel terminals. This condition poses shock and fire hazards and requires assessment by a qualified electrician. Why the other choices are wrong: Damage caused during the last panel service might affect a few wires, not the general condition of crumbling insulation. A wiring type that is inherently unsafe when new is false; it was code-compliant when installed. Normal appearance requiring no comment is dangerously incorrect; deteriorated insulation is a significant safety concern. Exam tip: Brittle, crumbling insulation on old wiring is a material defect due to age, not a cosmetic issue.

6. Fuses larger than the circuit conductors warrant are found in an older fuse panel. What is this called?

An overfused circuit
BA bonded neutral condition
CA parallel service arrangement
DAn unbalanced load distribution

Why A is correct

Why this is correct: The governing concept is overcurrent protection: the fuse or breaker must be sized to protect the circuit conductors. A fuse with a higher amperage rating than the conductors are rated for allows excessive current to flow, which can overheat the wires and create a fire hazard. Why the other choices are wrong: "A bonded neutral condition" refers to an improper neutral-ground connection. "A parallel service arrangement" describes a specific utility service setup. "An unbalanced load distribution" refers to load spread across phases in a panel. Exam tip: "Overfused" is the direct term for an oversized protective device, whether fuse or breaker.

7. Solid aluminum branch-circuit wiring from the 1960s and 1970s raises which specific concern?

Connections loosen and overheat at terminations
BThe conductors cannot carry residential loads
CAluminum conducts electricity at a lower voltage
DThe wiring must be replaced before any sale

Why A is correct

Why this is correct: Solid aluminum wiring from that era has different thermal expansion properties than copper. At connections (terminations), this can cause loosening over time, leading to increased resistance, overheating, and fire risk. The problem is at the connection points, not the wire itself. Why the other choices are wrong: "The conductors cannot carry residential loads" is incorrect; properly installed and terminated aluminum wiring can carry rated loads. "Aluminum conducts electricity at a lower voltage" is a false statement; voltage is a property of the circuit, not the conductor material. "The wiring must be replaced before any sale" is an overstatement; proper remediation at terminations is often sufficient. Exam tip: The key concern with old aluminum wiring is not the wire in the wall, but the connections at devices and panels.

8. The dead front cover is missing from an energized panel. How should the inspector treat this?

As an immediate safety hazard to be reported prominently
BAs a maintenance item to be corrected at convenience
CAs acceptable if the panel is in a locked room
DAs outside the scope of a general inspection

Why A is correct

Why this is correct: A missing dead front cover exposes live electrical components (bus bars, terminals), creating a severe shock hazard. This is an immediate safety issue that must be reported prominently so the client understands the urgency of correction. Why the other choices are wrong: As a maintenance item to be corrected at convenience is wrong because an exposed electrical hazard requires prompt attention, not deferred maintenance. As acceptable if the panel is in a locked room is wrong because accessibility does not mitigate the hazard; authorized persons (like homeowners) are still at risk. As outside the scope of a general inspection is wrong because exposed live parts are a visible safety defect clearly within the inspection scope. Exam tip: Missing panel covers are a serious, immediate safety hazard. Always flag them for urgent repair.

9. What does the inspector look for at the panel to assess how branch circuits are labelled?

AWhether the labels match the manufacturer's template
BWhether the panel index is printed rather than written
Whether circuits are identified clearly and accurately
DWhether every circuit is numbered in sequence

Why C is correct

Why this is correct: A clear and accurate panel directory is a safety feature. It allows anyone (homeowner, electrician, firefighter) to quickly and safely identify which breaker controls which circuit, especially during an emergency. Legibility and accuracy are key. Why the other choices are wrong: "Whether the labels match the manufacturer's template" is irrelevant; handwritten labels are acceptable if clear. "Whether the panel index is printed rather than written" is incorrect; the format doesn't matter, clarity does. "Whether every circuit is numbered in sequence" is not required; identification by area/use is standard. Exam tip: The directory's purpose is functional safety, not aesthetics. Blank, vague, or incorrect labels are a defect.

10. Why does an inspector look at receptacles for evidence of scorching around the slots?

Scorching indicates the device has been overloaded or arcing
BScorching shows the receptacle was painted over
CDiscolouration establishes the device's age
DScorching means the circuit is ungrounded

Why A is correct

Why this is correct: Scorching or discoloration on a receptacle is a visual clue of past overheating. Overheating occurs due to high resistance at the contact points, caused by a loose plug connection, worn contacts, or an overloaded circuit. This condition can lead to arcing and is a fire hazard. Why the other choices are wrong: Scorching shows the receptacle was painted over is incorrect; paint would cover the slots, not cause scorching from within. Discolouration establishes the device's age is wrong; age may cause yellowing, but localized scorching indicates a problem. Scorching means the circuit is ungrounded is false; a grounded circuit can still have a scorched receptacle from overheating. Exam tip: Scorching = heat = a problem. It's a visible sign of an internal fault.

11. Why does an inspector note that a circuit serves both indoor and outdoor receptacles?

Outdoor conditions can trip protection affecting indoor outlets
BMixed circuits must have twice the conductor size
COutdoor receptacles cannot share a neutral
DSuch circuits require a dedicated grounding electrode

Why A is correct

Why this is correct: The governing concept is circuit sharing and the practical consequence of GFCI or AFCI protection. Outdoor receptacles are required to have GFCI protection. If an outdoor receptacle on a shared circuit trips due to moisture, it de-energizes the entire circuit, including critical indoor appliances. Why the other choices are wrong: Mixed circuits must have twice the conductor size is not an NEC requirement. Outdoor receptacles cannot share a neutral is incorrect; they can share a neutral in a multi-wire branch circuit if properly configured. Such circuits require a dedicated grounding electrode is wrong; grounding electrodes are for the service, not individual circuits. Exam tip: Shared circuits mean shared fate. A trip outdoors can cause a nuisance outage indoors.

12. Why does an inspector open a receptacle cover plate only where it is safe and appropriate?

ARemoving plates is prohibited by the standard
BCover plates cannot be refitted once removed
Opening energised devices carries risk
DPlates conceal the circuit's identification

Why C is correct

Why this is correct: The governing principle is that a home inspection is visual and non-invasive. Opening an energized electrical device exposes live terminals, creating an unnecessary risk of electric shock or short circuit for the inspector. The information gained is not proportionate to the safety hazard. Why the other choices are wrong: Removing plates is prohibited by the standard is too absolute; standards limit but do not universally prohibit removal. Cover plates cannot be refitted once removed is factually incorrect; plates are designed to be removable. Plates conceal the circuit's identification is wrong; circuit identification is typically at the panel, not behind a cover plate. Exam tip: Safety first. If a task is risky and non-essential to the visual inspection, do not perform it.

13. Why is buried knob-and-tube wiring in contact with loose insulation a concern?

AThe insulation increases the circuit's total resistance
BThe wiring cannot be identified once it is covered
CThe insulation will corrode the conductors over time
The wiring was designed to dissipate heat into open air

Why D is correct

Why this is correct: Knob-and-tube wiring relies on air space around the conductors to dissipate heat generated by current flow. Loose insulation packed around the wires traps this heat, which can accelerate insulation breakdown and create a fire hazard over time. Why the other choices are wrong: "The insulation increases the circuit's total resistance" is incorrect; circuit resistance is in the wire, not the thermal insulation. "The wiring cannot be identified once it is covered" is a practical issue but not the primary safety hazard. "The insulation will corrode the conductors over time" is wrong; corrosion is not a typical result of contact with building insulation. Exam tip: For K&T, remember the design principle: heat dissipation through air space. Blocking that space creates a problem.

14. Why might a refrigerator on a shared GFCI circuit be a practical concern?

ARefrigerators cannot operate on protected circuits
A nuisance trip spoils food before anyone notices
CThe compressor will damage the GFCI device
DProtected circuits deliver reduced voltage

Why B is correct

Why this is correct: The governing concept is the practical consequence of nuisance GFCI tripping on essential appliances. As the original explanation notes, a trip on a shared circuit while occupants are away can spoil food in the refrigerator, which is why dedicated circuits are preferred. Why the other choices are wrong: "Refrigerators cannot operate on protected circuits" is incorrect; they can operate fine on GFCI circuits. "The compressor will damage the GFCI device" is wrong; compressor startup does not typically damage GFCIs. "Protected circuits deliver reduced voltage" is incorrect; GFCI protection does not affect voltage. Exam tip: The concern with a fridge on a GFCI is food spoilage from an unnoticed trip, not electrical incompatibility.

15. Why might an arc fault device trip on a circuit that appears to work normally?

The device is sensing an arcing signature somewhere
BThe circuit is drawing more current than rated
CThe device requires periodic replacement
DThe circuit voltage is above the device's range

Why A is correct

Why this is correct: Arc Fault Circuit Interrupters (AFCIs) are designed to detect the unique electrical signature of an arc (a dangerous spark). They can trip due to hidden arcing from damaged wires or loose connections, even if all connected devices appear to work. Why the other choices are wrong: An overload (drawing more current) would trip the standard overcurrent protection, not necessarily the AFCI. AFCIs do not require periodic replacement. Circuit voltage being out of range is not a typical AFCI function. Exam tip: AFCI trips indicate a potential hidden arcing fault, not necessarily an overload or a visible problem.

117 more Electrical questions

Answers and explanations for these are in the study app.

A 60-amp electrical service in a home with central air conditioning and electric appliances is:
A branch circuit conductor shows melted insulation near a termination. What does this indicate?
A breaker in the panel is not connected to any conductor. How should this be reported?
A ceiling fan is mounted on a box not identified as suitable for fan support. What is the concern?
A circuit serving a bathroom also serves receptacles in an adjacent bedroom. What is the concern?
A coin or metal disc is found behind a fuse in an older panel. What has been done?
A drip loop below the weatherhead exists to:
A Federal Pacific or similar legacy panel with a documented reliability history should be reported by:
A fuse panel in which fuses larger than the circuit rating have been installed is a concern because:
A GFCI receptacle does not trip when its test button is pressed. What should the report say?
A GFCI receptacle is installed but its test button is inaccessible behind a fixed appliance. Why is this reported?
A GFCI receptacle protecting downstream outlets should be:
A GFCI that trips whenever a specific appliance is plugged in indicates:
A GFCI trips immediately every time it is reset. What does this suggest?
A ground rod is visible with its clamp corroded and the conductor loose. What is the effect?
A grounding electrode conductor connects the electrical system to:
A grounding electrode conductor has been spliced with a wire nut. Why is this reported?
A junction box in an attic covered by blown insulation is a concern because:
A junction box in the attic has no cover and spliced conductors are visible. Why is the cover required?
A kitchen has a single circuit serving the refrigerator, microwave and countertop receptacles. What is the likely consequence?
A light fixture in a clothes closet sits directly above the shelf where items are stored. What is the concern?
A light switch that feels warm to the touch during normal use indicates:
A main breaker is rated higher than the panel's marked bus rating. Why is this reported?
A panel directory that is blank or inaccurate affects:
A panel is installed in a clothes closet. Why is this reported?
A panel with a double-tapped breaker — two conductors under one lug not rated for it — is a concern because:
A pull-chain light fixture is installed in an attic with no wall switch. Why does an inspector note this?
A receptacle tester indicates reversed polarity. What does this mean?
A service mast that is bent or leaning where the utility drop attaches:
A service panel mounted on the exterior with no rain-tight enclosure is:
A shed has been built directly beneath the service drop. Why does this matter?
A single GFCI device protects several downstream receptacles. How should the inspector verify this?
A subpanel fed by a three-wire feeder in a detached structure built recently:
A subpanel is fed by a three-conductor cable with no separate equipment ground. What is the concern?
A switch controls a receptacle in a bedroom rather than a ceiling fixture. How should this be reported?
A three-prong receptacle installed on a two-wire circuit without GFCI protection is:
A three-prong receptacle tests as having no equipment ground. What has likely happened?
AFCI protection differs from GFCI in that AFCI is designed to:
Aluminum branch wiring has been remediated at receptacles using a listed method. How should this be reported?
Aluminum wiring at receptacles connected with standard wire nuts rather than approved connectors:
An extension cord wired permanently into a ceiling fixture is a concern because:
An inspector finds a 20-amp breaker protecting a circuit wired in 14 AWG copper. How should this be reported?
An inspector finds stored boxes stacked against an electrical panel. Why is this reported?
An inspector finds the grounding electrode conductor clamped to a metal water pipe downstream of a plastic repair section. What is the concern?
An inspector identifies a panel brand with a documented history of breakers failing to trip. What is the appropriate report language?
An older house has a two-wire circuit with no ground. What GFCI arrangement is commonly used there?
An open knockout is found on the side of an energised panel. What is the concern?
An outdoor receptacle has a flat cover that closes only when nothing is plugged in. What is the concern?
Bonding of metal gas piping to the electrical grounding system serves to:
Breakers in a panel that do not match the panel's listed manufacturer are a concern because:
Breakers larger in amperage than the conductors they protect are a concern because:
Breakers of a different manufacturer from the panel are found installed. Why is this reported?
Cloth-insulated wiring is found with the insulation crumbling at the panel. Why is this reported?
Conductors are found spliced outside any enclosure and wrapped in tape above a ceiling. How should this be reported?
Extension cords are found running through walls and serving permanent appliances. Why is this reported?
GFCI protection detects a hazard by:
GFCI protection is commonly recommended at receptacles:
How does the purpose of an arc fault device differ from that of a ground fault device?
How should an inspector describe a panel type with a reported history of problems when the breakers appear to function?
How should an inspector describe the electrical service capacity?
How should an inspector describe wiring methods they cannot identify with confidence?
How should an inspector report a system that mixes knob-and-tube with modern wiring?
How should an inspector treat a smart or connected device installed in place of a standard one?
In a subpanel, neutrals and grounds must be:
In a subpanel, the inspector finds neutrals and equipment grounds sharing a single bonded bar. Why does this matter?
Knob-and-tube wiring found buried in blown attic insulation is a concern because:
Knob-and-tube wiring has been spliced to modern cable inside a wall cavity. What is the concern?
Metal water piping used as a grounding electrode should be:
Missing knockout covers on a panel's enclosure should be reported because:
Openings remain in a panel where breakers were removed. What is the concern?
Romex-type cable running exposed across a basement wall below about seven feet should be:
Service entrance conductors pass within easy reach of a second-floor window. What is the concern?
Service entrance conductors that are frayed or have cracked insulation at the weatherhead should be:
The panel directory lists circuits that do not match what the breakers actually control. Why does this matter?
Two conductors are found under a single breaker terminal not listed for it. What is the concern?
What characterises knob-and-tube wiring as an inspection concern?
What does a ground fault circuit interrupter protect against?
What does an inspector conclude from finding several extension cords under rugs?
What does an inspector note about a light fixture installed in a clothes closet?
What does an inspector note where GFCI protection is provided at the breaker rather than the receptacle?
What does an inspector observe about breaker handles that do not align with their neighbours?
What does an inspector observe where a service enters below grade rather than overhead?
What does the inspector examine at a service mast?
What is the concern when a house has had its metal water service replaced with plastic?
What is the essential difference between grounding and bonding?
What is the inspector examining when the service drop is observed at the point of attachment?
What is the purpose of bonding the metal water piping system?
What should an inspector observe about a meter enclosure showing burn marks around its base?
Which conductor and breaker pairing is correct for a copper branch circuit?
Why does an inspector check that a water meter has a bonding jumper across it?
Why does an inspector look at how cables enter a panel enclosure?
Why does an inspector look for evidence of water entry inside a panel enclosure?
Why does an inspector look for more than one grounding electrode at some services?
Why does an inspector note a light fixture hanging directly from its supply conductors?
Why does an inspector note a panel that has no main disconnecting means within it?
Why does an inspector note cable stapled tightly enough to deform its sheathing?
Why does an inspector note ceiling fixtures with heat damage in an older house?
Why does an inspector note conductors of two different metals joined at a device terminal?
Why does an inspector note the absence of a visible service disconnect label or marking?
Why does an inspector note vegetation growing against a service mast or drop?
Why does an inspector note where the grounding electrode conductor is subject to physical damage?
Why does an inspector note whether service entrance conductors show signs of overheating at the main disconnect?
Why does an inspector note whether the main disconnect is readily accessible?
Why does an inspector note whether the service equipment is bonded to the grounding electrode system?
Why does an inspector report a bonding jumper that appears loose at its clamp?
Why does an inspector report the absence of GFCI protection in a wet location even where it was not required when the house was built?
Why does an inspector report the presence of a sub-panel fed from a subpanel in an older house?
Why does an inspector test a GFCI with its own test button rather than an external tester alone?
Why does an inspector test a representative number of receptacles rather than all of them?
Why does an inspector test protection devices at the start of the electrical inspection rather than the end?
Why is a fuse panel not by itself a defect?
Why is metal gas piping bonded to the electrical system?
Wire connections made outside a junction box in an attic are a concern because:
Wiring for an added circuit runs on the exterior of the building without conduit. What is the concern?
Wiring in a garage runs across the wall surface without protection to a height of four feet. What is the concern?
Wiring in an unfinished basement runs across the face of the joists at head height. What is the concern?
Wiring run through a stud without a nail plate where the hole is close to the stud's edge:

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