NEC 2023 Practice Test

A circuit breaker protecting a non-motor-operated appliance shall not exceed 20 amperes if the overcurrent rating is not marked and the appliance is rated _______or less.

• 12.3 amperes

• 15.3 amperes

• 14.3 amperes

• 13.3 amperes

Answer explanation

422.11 (E)

What is the full-load current rating on the secondary side terminals of a 75 kVA, three-phase transformer having a 277/480 volt primary and a 208Y/120 volt secondary?

• 156 amperes

• 208 amperes

• 360 amperes

• 362 amperes

Answer explanation

75 x 1000 = 75000 / 208 x 1.732 = 75000/360.25 = 208

A 150 kVA, single-phase transformer having a secondary voltage of 120/240 Volts is to be installed in a multi-family dwelling. The current available at the Secondary terminals is ____________.

• 329 amperes

• 421 amperes

• 625 amperes

• 729 amperes

Answer explanation

15000 / 240 = 625

When installed on the service of a building or structure, a Type 2 SPD shall be connected----.

• on the line side of the service disconnect overcurrent device

• on the load side of the service disconnect device

• on the meter housing

• at the final overcurrent device

Answer explanation

242.14 (A)

The maximum number of No. 10 AWG conductors in a 4 inch x 1-1/4 inch square box is ________.

• Seven

• Four

• Five

• Six

Answer explanation

Table 314.16 (A)

The minimum clearance above a diving platform of a swimming pool and 120/240-volt, single-phase, messenger supported, service-drop conductors is ____________.

• 14-1/2 feet

• 22-1/2 feet

• 19 feet

• 21 feet

Answer explanation

Table 680.9 (A)

The minimum space between the bottom of a 600-volt rated switchboard and non-insulated bus bars mounted in the switchboard cabinet is ------.

• 6 inches

• 8 inches

• 10 inches

• 12 inches

Answer explanation

Table 408.5

Given: 80-ampere, 240-volt circuit located 200 feet from panel-board. Conductors No. 3 THHN/THWN. Assuming K= 12.9 what is the voltage drop of this circuit?

• 6 volts

• 4 volts

• 9.2 volts

• 7.84 volts

Answer explanation

2 x k x amps x length / CMIS chapter 9 table 8

2 x 12.9 x 80 x 200 / 52620 412,800/52620 = 7.839

In a health care facility, low-voltage electrical equipment that is likely to become energized that is frequently in contact with the bodies of patients shall operate on a voltage of _________or less of the equipment is not approved as intrinsically safe, double insulated, or moisture resistant.

• 10 volts

• 24 volts

• 100 volts

• 120 volts

Answer explanation

517.64 (A) (1)

Where a trade size ½-rigid metal conduit (RMC) is to be installed in a Class 1 location and a trade size ½ inch conduit seal is required, the minimum thickness of the sealing compound shall not be less than ____________.

• 3/8 Inch

• 1/2 inch

• 5/8 inch

• 3/4 inch

Answer explanation

501.15 (C) (3)