Free Electrician Practice Test (20 Questions) | ExamsLib

Question 1

Which of the following is a recognized grounding electrode type?

Accepted Answer

A concrete-encased electrode (Ufer ground)

Answer

A copper pipe used as a drain line

Answer

Any metal object buried 6 inches below grade

Answer

A plastic water main

Question 2

What is the purpose of adding two small appliance branch circuit loads (each at 1,500 VA) to a residential load calculation?

Accepted Answer

To account for kitchen and dining area receptacle loads where portable appliances are likely used

Answer

To size the circuit breakers for the laundry room

Answer

To calculate the load for fixed appliances only

Answer

To determine how many lighting outlets are needed

Question 3

What is the primary purpose of equipment grounding in an electrical system?

Accepted Answer

To provide a low-impedance fault-current path back to the source so overcurrent devices can operate

Answer

To improve the power factor of the circuit

Answer

To stabilize the voltage on the ungrounded conductors

Answer

To reduce the resistance of the neutral conductor

Question 4

In a residential service, where is the first and only permitted point at which the neutral (grounded conductor) and the equipment grounding conductor may be connected together?

Accepted Answer

At the service disconnect (main panel) where the main bonding jumper is installed

Answer

At each sub-panel throughout the home

Answer

Only at the main breaker handle itself

Answer

At the grounding electrode rod only

Question 5

A building has a concrete-encased electrode (Ufer ground) consisting of 20 ft of 4 AWG bare copper encased in the concrete footings. A ground rod at the same location can only be driven to 6 ft before hitting bedrock. Under NEC 250.53(G), which of the following correctly describes the permitted installation of that ground rod?

Accepted Answer

The rod may be driven at an angle not exceeding 45 degrees from vertical, or buried horizontally at least 30 inches deep, and still qualifies as an electrode

Answer

The rod must be rejected; only the concrete-encased electrode may be used when rock prevents full depth

Answer

A second concrete-encased electrode must replace the rod whenever rock is encountered within 8 ft of grade

Answer

The rod must be extended with a coupling to reach a minimum depth of 8 ft below the rock surface

Question 6

What is the function of the grounding electrode conductor (GEC)?

Accepted Answer

To connect the grounded system conductor or equipment to a grounding electrode

Answer

To carry load current from the panel to branch circuits

Answer

To bond two separate panels together

Answer

To provide a return path for fault current on branch circuits

Question 7

A 240 V, 20 A circuit feeds a water heater. What is the load in volt-amperes (VA)?

Accepted Answer

4,800 VA

Answer

260 VA

Answer

480 VA

Answer

2,400 VA

Question 8

A 120/240 V single-phase service feeds a home. The total calculated load is 28,800 VA. What is the minimum service ampacity required?

Accepted Answer

120 A

Answer

60 A

Answer

100 A

Answer

200 A

Question 9

A 480/277V, 3-phase, 4-wire wye service uses 500 kcmil copper ungrounded conductors. According to NEC Table 250.66, what is the minimum size copper grounding electrode conductor required?

Accepted Answer

2/0 AWG copper

Answer

1/0 AWG copper

Answer

3/0 AWG copper

Answer

4/0 AWG copper

Question 10

Using the NEC optional method (220.82) for a 240-volt single-phase service, the first 10 kVA of total calculated load is taken at 100% and the remainder at 40%. If a home's total connected load before demand factors is 48 kVA, what is the minimum calculated demand load in kVA?

Accepted Answer

23.2 kVA

Answer

19.2 kVA

Answer

25.6 kVA

Answer

30.4 kVA

Free Electrician Practice Test

Question 1

Which of the following is a recognized grounding electrode type?

Question 2

What is the purpose of adding two small appliance branch circuit loads (each at 1,500 VA) to a residential load calculation?

Question 3

What is the primary purpose of equipment grounding in an electrical system?

Question 4

In a residential service, where is the first and only permitted point at which the neutral (grounded conductor) and the equipment grounding conductor may be connected together?

Question 5

Question 6

What is the function of the grounding electrode conductor (GEC)?

Question 7

A 240 V, 20 A circuit feeds a water heater. What is the load in volt-amperes (VA)?

Question 8

A 120/240 V single-phase service feeds a home. The total calculated load is 28,800 VA. What is the minimum service ampacity required?

Question 9

A 480/277V, 3-phase, 4-wire wye service uses 500 kcmil copper ungrounded conductors. According to NEC Table 250.66, what is the minimum size copper grounding electrode conductor required?

Question 10

Using the NEC optional method (220.82) for a 240-volt single-phase service, the first 10 kVA of total calculated load is taken at 100% and the remainder at 40%. If a home's total connected load before demand factors is 48 kVA, what is the minimum calculated demand load in kVA?

Question 11

Using Ohm's Law, if a 120 V circuit has a resistance of 12 ohms, what is the current flowing?

Question 12

A residential dwelling has 2,000 sq ft of living space. Using 3 VA/sq ft for general lighting and applying 100% demand on the first 3,000 VA and 35% on the remainder, what is the calculated general lighting demand load?

Question 13

What is the primary purpose of grounding an electrical system?

Question 14

In a standard residential load calculation, what general lighting load value (in VA per square foot) is commonly used for dwellings?

Question 15

Which NEC term describes the conductive connection that joins together metal parts of an electrical system to establish electrical continuity, but is NOT intended to carry fault current to earth?

Question 16

Two separate buildings on the same property are supplied from a common service. An equipment grounding conductor is run with the feeder to the second building. Which statement is correct regarding the neutral-to-ground bond at the second building's panelboard?

Question 17

When calculating the minimum number of small-appliance branch circuits for a dwelling's kitchen and dining areas, the NEC specifies at least how many 20-ampere circuits?

Question 18

Question 19

Bonding is required on metal gas piping in a building primarily to:

Question 20

A single ground rod is installed and tested. Its measured resistance to earth is 35 ohms. What additional action is generally required?