CBC Mechanical, Electrical & Plumbing (MEP) Systems 3

Question 1

What is the standard residential electrical service voltage in the United States?

Accepted Answer

120/240 volts, single-phase

Answer

110/220 volts, single-phase

Answer

208/480 volts, three-phase

Answer

240/480 volts, three-phase

Question 2

Which pipe material is most commonly used for residential drain, waste, and vent (DWV) systems in the US?

Accepted Answer

PVC Schedule 40

Answer

Type L copper

Answer

CPVC

Answer

Galvanized steel

Question 3

What is the minimum wire gauge (AWG) required for a 20-amp branch circuit per the NEC?

Accepted Answer

12 AWG

Answer

14 AWG

Answer

10 AWG

Answer

8 AWG

Question 4

In a split-system air conditioner, which component is located outdoors?

Accepted Answer

Condenser unit

Answer

Evaporator coil

Answer

Air handler cabinet

Answer

Blower motor

Question 5

What is the function of a condensate drain in an air conditioning system?

Accepted Answer

To remove moisture collected by the evaporator coil during cooling

Answer

To drain excess refrigerant when servicing the system

Answer

To drain the boiler during seasonal winterization

Answer

To provide a pressure-relief outlet for refrigerant

Question 6

Which type of valve allows fluid flow in only one direction and prevents backflow?

Accepted Answer

Check valve

Answer

Gate valve

Answer

Ball valve

Answer

Globe valve

Question 7

Which code requires arc-fault circuit interrupter (AFCI) protection in residential sleeping areas and most living spaces?

Accepted Answer

National Electrical Code (NEC)

Answer

OSHA 29 CFR 1910 General Industry Standard

Answer

International Mechanical Code (IMC)

Answer

International Plumbing Code (IPC)