Home Inspector Electrical Systems Practice Questions
Electrical Systems makes up 4 of every 50 questions on a Tigertest Home Inspector practice test. Here are 10 of the 16 questions on it, each with the answer and the reason.
Updated by the Tigertest team. Based on the EBPHI content outline for the National Home Inspector Examination. Original questions; 50 per test, weighted like the real 200-question exam. Not affiliated with EBPHI.
1. Two conductors under one terminal of a breaker that is not listed for two wires is called:
- A.An open splice
- B.A double tap
- C.A bootleg ground
- D.A shared neutral
Answer: B. Most breakers are listed for one conductor per terminal. A second wire may not be held tightly, leading to arcing and overheating.
2. Which panelboard is widely reported for breakers that may fail to trip on overload?
- A.Siemens QP
- B.Eaton Type BR
- C.Square D Homeline
- D.FPE Stab-Lok
Answer: D. Federal Pacific Stab-Lok (and Zinsco) panels are known problem panels. Inspectors report them and recommend evaluation by an electrician.
3. Solid-conductor aluminum branch circuit wiring from the mid-1960s to the early 1970s is a concern because:
- A.Connections can overheat
- B.It corrodes inside drywall
- C.It cannot carry 15 amps
- D.It cannot be grounded
Answer: A. Aluminum expands, creeps and oxidizes at terminals made for copper, so connections loosen and overheat. The wire itself is not the main issue.
4. A recognized permanent repair for aluminum branch wiring at receptacles and switches is:
- A.Using push-in terminals
- B.Painting the joints with sealant
- C.Pigtails with listed connectors
- D.Wrapping joints in tape
Answer: C. Copper pigtails joined with connectors listed for aluminum to copper, such as crimp or purpose-made connectors, remove the problem connections.
5. A plug-in tester shows reversed polarity at a receptacle. This means:
- A.GFCI protection is missing
- B.Two circuits share a neutral
- C.Hot and neutral are swapped
- D.The ground is open
Answer: C. Reversed polarity puts the hot on the wide neutral slot, so the shell of a lamp socket can be energized even with the switch off.
6. Rust and water stains inside a service panel most often trace back to:
- A.Water entering at the service entrance
- B.An undersized neutral conductor
- C.Reversed polarity at receptacles
- D.Breakers loaded beyond their rating
Answer: A. Water that runs down the service drop or mast, or through an unsealed entry, collects inside the panel and corrodes breakers and bus bars.
7. A 14 AWG copper branch circuit protected by a 30-amp breaker is an example of:
- A.An undersized service
- B.A double tap
- C.Reverse polarity
- D.Overfusing
Answer: D. The breaker must protect the wire. 14 AWG copper is normally limited to 15 amps, so a 30-amp breaker lets the wire overheat before it trips.
8. Two white neutral wires under one screw on a neutral bar are reported because:
- A.It reverses circuit polarity
- B.They may not be held securely
- C.Neutrals belong on the ground bar
- D.White wires carry no current
Answer: B. Most neutral terminals are listed for one conductor. A second wire may loosen, and disturbing one circuit can loosen the other's neutral.
9. A home's service rating is generally the lowest rating among the service conductors, the panel and the:
- A.Grounding conductor
- B.Main disconnect
- C.Largest branch breaker
- D.Range circuit breaker
Answer: B. The service is only as large as its smallest part: service entrance conductors, panel rating or main disconnect. Branch breakers do not set it.
10. Which location is not allowed for a residential panelboard with overcurrent devices?
- A.An unfinished basement
- B.An exterior wall
- C.An attached garage
- D.A clothes closet
Answer: D. Overcurrent devices may not be in clothes closets or bathrooms, where clothing and other combustibles crowd them and access is poor.
Practice all 16 electrical systems questions, and the rest of the 200-question bank, in the free Home Inspector training sets. Questions you miss come back until you have mastered them.
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