CRC CRC Electrical, Plumbing & Mechanical Systems

Question 1

In residential wiring, what is the maximum number of 20-ampere branch circuits required to serve kitchen counter receptacles per the NEC?

Accepted Answer

At least two small-appliance circuits

Answer

One dedicated 15-amp circuit

Answer

Three 20-amp circuits minimum

Answer

A single 30-amp circuit

Question 2

A residential plumber installs a P-trap below a lavatory sink. What is the P-trap's primary function?

Accepted Answer

To hold water that blocks sewer gases from entering the home

Answer

To increase water pressure at the fixture

Answer

To filter debris from the drain line

Answer

To regulate hot and cold water mixing

Question 3

What type of HVAC system circulates conditioned air through a network of ducts to multiple rooms in a home?

Accepted Answer

Forced-air system

Answer

Radiant heating system

Answer

Mini-split (ductless) system

Answer

Baseboard hydronic system

Question 4

When installing electrical outlets in a bathroom, the NEC requires them to be protected by which device?

Accepted Answer

Ground Fault Circuit Interrupter (GFCI)

Answer

Arc Fault Circuit Interrupter (AFCI)

Answer

Surge protector

Answer

Double-pole breaker

Question 5

What is the minimum slope required for a residential drain pipe to ensure proper drainage per most plumbing codes?

Accepted Answer

1/4 inch per foot (2% grade)

Answer

1/8 inch per foot (1% grade)

Answer

1/2 inch per foot (4% grade)

Answer

1 inch per foot (8% grade)

Question 6

Which refrigerant is most commonly used in modern residential air conditioning systems due to lower ozone depletion potential?

Accepted Answer

R-410A

Answer

R-22 (Freon)

Answer

R-12

Answer

R-502