Licensed Electrical Contractor Branch Circuit Calculations Questions and Answers

Question 1

A 120V branch circuit in a commercial office supplies a continuous lighting load of 13 amperes. What is the minimum required rating for the overcurrent protective device (OCPD) for this circuit?

Accepted Answer

20A

Answer

15A

Answer

25A

Answer

30A

Question 2

What is the calculated load, in volt-amperes (VA), for a general-purpose branch circuit in a commercial building that supplies 12 duplex receptacles?

Accepted Answer

2,160 VA

Answer

1,800 VA

Answer

1,440 VA

Answer

1,500 VA

Question 3

A new single-family dwelling is being wired. Which of the following is a requirement for the small-appliance branch circuits serving the kitchen countertops?

Accepted Answer

A minimum of two 20-ampere circuits are required.

Answer

They must be rated at 15 amperes.

Answer

They are permitted to supply lighting fixtures within the kitchen.

Answer

They can also serve receptacles in the attached garage.

Question 4

A conduit is installed containing eight current-carrying THHN/THWN copper conductors. According to NEC Table 310.15(C)(1), what adjustment factor must be applied to the ampacity of these conductors?

Accepted Answer

70%

Answer

80%

Answer

50%

Answer

45%

Question 5

What is the calculated branch-circuit demand load for a single 14 kW household electric range installed in a dwelling unit, using the standard calculation method?

Accepted Answer

8.8 kW

Answer

14 kW

Answer

8.0 kW

Answer

11.2 kW

Question 6

A 20-ampere, 120-volt branch circuit supplies a fixed electric heater with a rating of 1,600 VA (a continuous load) and two general-purpose receptacles. What is the maximum permissible non-continuous load that can be connected to the receptacles?

Accepted Answer

400 VA

Answer

800 VA

Answer

2,400 VA

Answer

1,600 VA

A 120V branch circuit in a commercial office supplies a continuous lighting load of 13 amperes.What is the minimum required rating for the overcurrent protective device (OCPD) for this circuit?

A 120V branch circuit in a commercial office supplies a continuous lighting load of 13 amperes.
What is the minimum required rating for the overcurrent protective device (OCPD) for this circuit?