Colorado Master Electrician License
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Colorado Master
Electrician Exam Prep & Study Guide
1. What is the primary purpose of the National Electrical Code?
A. To establish electrical utility rates
B. To provide standards for safe electrical installations
C. To determine electrician wages
D. To regulate electrical equipment manufacturers
Answer: To provide standards for safe electrical installations
Rationale: The NEC establishes minimum requirements intended to safeguard
people and property from hazards arising from the use of electricity.
2. In a balanced three-phase system, what is the phase displacement between
each phase?
A. 60 degrees
B. 90 degrees
C. 120 degrees
D. 180 degrees
,Answer: 120 degrees
Rationale: The three phase conductors of a balanced three-phase system are
electrically separated by 120 degrees.
3. Which formula represents Ohm's law?
A. P = EI
B. E = IR
C. P = I²R
D. E = P/R
Answer: E = IR
Rationale: Ohm's law states that voltage equals current multiplied by
resistance.
4. A 120-volt circuit draws 15 amperes. What is the approximate power
consumption?
A. 1,200 watts
B. 1,500 watts
C. 1,800 watts
D. 2,400 watts
Answer: 1,800 watts
Rationale: Using P = E × I, 120 volts × 15 amperes = 1,800 watts.
5. What happens to total resistance when resistors are connected in parallel?
A. It increases above the largest resistance
B. It equals the sum of all resistances
C. It decreases below the smallest branch resistance
D. It becomes infinite
Answer: It decreases below the smallest branch resistance
,Rationale: Parallel current paths reduce total circuit resistance because current
has multiple paths through which it can flow.
6. Which instrument is normally used to measure current?
A. Voltmeter
B. Ohmmeter
C. Ammeter
D. Megohmmeter
Answer: Ammeter
Rationale: An ammeter measures current and is normally connected so that the
circuit current passes through the instrument.
Services, Feeders, and Branch Circuits
7. What is the primary purpose of a service disconnecting means?
A. To increase system voltage
B. To disconnect the premises wiring from the supply
C. To regulate power factor
D. To reduce conductor resistance
Answer: To disconnect the premises wiring from the supply
Rationale: The service disconnect provides a means of disconnecting the building
or premises wiring from the serving supply.
8. A dwelling has a calculated general lighting load of 4,500 VA. Using a
120/240-volt single-phase service, what current would this load represent if
it were entirely at 240 volts?
A. 9.375 A
B. 18.75 A
C. 37.5 A
D. 75 A
, Answer: 18.75 A
Rationale: Current equals VA divided by volts. Therefore, 4,500 VA ÷ 240 V =
18.75 A.
9. Which conductor normally carries current back from a 120-volt load to the
source?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral conductor
D. Bonding jumper
Answer: Neutral conductor
Rationale: In a typical 120-volt circuit, the neutral conductor serves as the
grounded circuit conductor and carries return current from the load.
10.What is the main function of a feeder?
A. Supply power from the final overcurrent device to individual receptacles only
B. Supply power from the service or another power source to branch-circuit
overcurrent devices
C. Provide only grounding connections
D. Supply only lighting loads
Answer: Supply power from the service or another power source to branch-
circuit overcurrent devices
Rationale: A feeder carries power from a service, separately derived system, or
other source to the final branch-circuit overcurrent devices.
11.Which type of load generally requires consideration of its continuous-load
rating when sizing a circuit?
A. A load operating for only a few minutes
B. A continuous load
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Colorado Master
Electrician Exam Prep & Study Guide
1. What is the primary purpose of the National Electrical Code?
A. To establish electrical utility rates
B. To provide standards for safe electrical installations
C. To determine electrician wages
D. To regulate electrical equipment manufacturers
Answer: To provide standards for safe electrical installations
Rationale: The NEC establishes minimum requirements intended to safeguard
people and property from hazards arising from the use of electricity.
2. In a balanced three-phase system, what is the phase displacement between
each phase?
A. 60 degrees
B. 90 degrees
C. 120 degrees
D. 180 degrees
,Answer: 120 degrees
Rationale: The three phase conductors of a balanced three-phase system are
electrically separated by 120 degrees.
3. Which formula represents Ohm's law?
A. P = EI
B. E = IR
C. P = I²R
D. E = P/R
Answer: E = IR
Rationale: Ohm's law states that voltage equals current multiplied by
resistance.
4. A 120-volt circuit draws 15 amperes. What is the approximate power
consumption?
A. 1,200 watts
B. 1,500 watts
C. 1,800 watts
D. 2,400 watts
Answer: 1,800 watts
Rationale: Using P = E × I, 120 volts × 15 amperes = 1,800 watts.
5. What happens to total resistance when resistors are connected in parallel?
A. It increases above the largest resistance
B. It equals the sum of all resistances
C. It decreases below the smallest branch resistance
D. It becomes infinite
Answer: It decreases below the smallest branch resistance
,Rationale: Parallel current paths reduce total circuit resistance because current
has multiple paths through which it can flow.
6. Which instrument is normally used to measure current?
A. Voltmeter
B. Ohmmeter
C. Ammeter
D. Megohmmeter
Answer: Ammeter
Rationale: An ammeter measures current and is normally connected so that the
circuit current passes through the instrument.
Services, Feeders, and Branch Circuits
7. What is the primary purpose of a service disconnecting means?
A. To increase system voltage
B. To disconnect the premises wiring from the supply
C. To regulate power factor
D. To reduce conductor resistance
Answer: To disconnect the premises wiring from the supply
Rationale: The service disconnect provides a means of disconnecting the building
or premises wiring from the serving supply.
8. A dwelling has a calculated general lighting load of 4,500 VA. Using a
120/240-volt single-phase service, what current would this load represent if
it were entirely at 240 volts?
A. 9.375 A
B. 18.75 A
C. 37.5 A
D. 75 A
, Answer: 18.75 A
Rationale: Current equals VA divided by volts. Therefore, 4,500 VA ÷ 240 V =
18.75 A.
9. Which conductor normally carries current back from a 120-volt load to the
source?
A. Equipment grounding conductor
B. Grounding electrode conductor
C. Neutral conductor
D. Bonding jumper
Answer: Neutral conductor
Rationale: In a typical 120-volt circuit, the neutral conductor serves as the
grounded circuit conductor and carries return current from the load.
10.What is the main function of a feeder?
A. Supply power from the final overcurrent device to individual receptacles only
B. Supply power from the service or another power source to branch-circuit
overcurrent devices
C. Provide only grounding connections
D. Supply only lighting loads
Answer: Supply power from the service or another power source to branch-
circuit overcurrent devices
Rationale: A feeder carries power from a service, separately derived system, or
other source to the final branch-circuit overcurrent devices.
11.Which type of load generally requires consideration of its continuous-load
rating when sizing a circuit?
A. A load operating for only a few minutes
B. A continuous load
