General Contractor License Mechanical, Electrical, and Plumbing Systems 3

Question 1

Under the NEC, what is the maximum circuit breaker size permitted for a 20-ampere-rated, 120V household receptacle circuit using 12 AWG copper wire?

Accepted Answer

20 amperes

Answer

15 amperes

Answer

25 amperes

Answer

30 amperes

Question 2

A contractor discovers the water supply pressure at a residential project measures 95 psi. What corrective action is required by code?

Accepted Answer

Install a pressure reducing valve (PRV) to bring pressure below 80 psi

Answer

Increase pipe diameter throughout

Answer

Add a check valve at the meter

Answer

No action is required below 100 psi

Question 3

What type of pipe expansion joint is required when installing long runs of copper water supply pipe to accommodate thermal expansion?

Accepted Answer

Expansion loop or offset

Answer

Gate valve

Answer

Dielectric union

Answer

Backflow preventer

Question 4

According to NFPA 70 (NEC), arc-fault circuit interrupter (AFCI) protection is required in which residential area?

Accepted Answer

All 120V, 15A and 20A branch circuits in dwelling unit bedrooms and most living areas

Answer

Garage and outdoor outlets only

Answer

Only circuits serving kitchen appliances

Answer

Only circuits in bathrooms and laundry rooms

Question 5

What is the primary purpose of a condensate neutralizer installed on a high-efficiency (condensing) gas furnace?

Accepted Answer

Raise the pH of acidic condensate before it enters the sanitary drain

Answer

Prevent freezing of the condensate drain line

Answer

Boost furnace efficiency by recovering heat from condensate

Answer

Filter sediment from the flue gas condensate

Question 6

When a general contractor subcontracts electrical work, who is ultimately responsible for ensuring all electrical installations meet NEC and local code requirements?

Accepted Answer

The general contractor, as the licensed contractor of record on the permit

Answer

The electrical subcontractor exclusively

Answer

The local utility company

Answer

The building owner