CBC Mechanical, Electrical & Plumbing (MEP) Systems

Question 1

What is the primary purpose of a pressure relief valve (PRV) on a hot water heater?

Accepted Answer

To prevent excessive pressure buildup that could cause an explosion

Answer

To regulate water temperature at the fixture

Answer

To control the flow rate of hot water

Answer

To filter sediment from the water supply

Question 2

What is the minimum slope required for horizontal drain pipes in residential plumbing per the IPC?

Accepted Answer

1/4 inch per foot

Answer

1/8 inch per foot

Answer

1/2 inch per foot

Answer

1 inch per foot

Question 3

Which electrical circuit type does the NEC require for kitchen countertop receptacles?

Accepted Answer

20-amp, 120-volt small appliance branch circuit

Answer

15-amp, 120-volt general purpose circuit

Answer

30-amp, 240-volt dedicated circuit

Answer

50-amp, 240-volt appliance circuit

Question 4

What is the primary function of a P-trap in a plumbing drain system?

Accepted Answer

To maintain a water seal that blocks sewer gases from entering the building

Answer

To prevent pipes from freezing in cold climates

Answer

To reduce water pressure at the fixture

Answer

To filter debris from drain water

Question 5

Which HVAC system type can provide both heating and cooling using a single piece of equipment?

Accepted Answer

Heat pump

Answer

Boiler with baseboard radiators

Answer

Evaporative cooler

Answer

Steam radiator system

Question 6

Which pipe material is approved for natural gas distribution inside residential buildings?

Accepted Answer

Black steel pipe or corrugated stainless steel tubing (CSST)

Answer

PVC (polyvinyl chloride)

Answer

CPVC (chlorinated polyvinyl chloride)

Answer

Type M copper tubing

Question 7

What is the function of a circuit breaker in a residential electrical panel?

Accepted Answer

To automatically disconnect a circuit when current exceeds safe limits

Answer

To convert AC power to DC for sensitive electronics

Answer

To increase voltage for high-demand appliances

Answer

To evenly distribute load across all circuits