NASCLA Accredited Trade
Examination for Electrical Contractors
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. Which fundamental electrical principle states that current is equal to
voltage divided by resistance?
A. Kirchhoff’s voltage law
B. Ohm’s law
C. Faraday’s law
D. Coulomb’s law
,Rationale: Ohm’s law is expressed as I = E/R, where current equals voltage
divided by resistance. It is fundamental to calculating circuit current,
voltage drop, and resistance relationships.
2. A 120-volt load draws 10 amperes. What is the approximate resistance
of the load?
A. 0.083 ohm
B. 1.2 ohms
C. 12 ohms
D. 1200 ohms
Rationale: Using Ohm’s law, R = E/I. Therefore, 120 volts divided by 10
amperes equals 12 ohms.
3. What is the electrical power consumed by a 240-volt load drawing 15
amperes?
A. 225 watts
B. 1,600 watts
C. 3,600 watts
D. 5,760 watts
,Rationale: Electrical power in a simple resistive circuit can be calculated
using P = E × I. Therefore, 240 × 15 = 3,600 watts.
4. What is the primary function of a circuit breaker?
A. To increase circuit voltage
B. To provide continuous grounding-current flow
C. To automatically interrupt current when a circuit experiences an
overcurrent condition
D. To reduce normal operating current
Rationale: A circuit breaker protects conductors and equipment by opening
the circuit when current exceeds its designed rating or when another
qualifying trip condition occurs.
5. What is the primary purpose of a fuse?
A. To increase available fault current
B. To provide a permanent connection regardless of current
C. To open a circuit when excessive current causes the fuse element to
operate
D. To regulate normal voltage
, Rationale: A fuse contains a calibrated element designed to open the
circuit when excessive current causes it to melt or otherwise interrupt the
circuit. It provides overcurrent protection.
6. Which conductor is normally identified as the grounded conductor in a
typical 120/240-volt single-phase system?
A. Green
B. White or gray
C. Orange
D. Bare copper only
Rationale: The grounded circuit conductor is generally identified by white
or gray insulation or other permitted identification methods. Green and
bare conductors are generally associated with equipment grounding.
7. What is the primary purpose of an equipment grounding conductor?
A. To carry normal load current continuously
B. To increase branch-circuit voltage
C. To provide an effective path for fault current so protective devices can
operate
Examination for Electrical Contractors
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. Which fundamental electrical principle states that current is equal to
voltage divided by resistance?
A. Kirchhoff’s voltage law
B. Ohm’s law
C. Faraday’s law
D. Coulomb’s law
,Rationale: Ohm’s law is expressed as I = E/R, where current equals voltage
divided by resistance. It is fundamental to calculating circuit current,
voltage drop, and resistance relationships.
2. A 120-volt load draws 10 amperes. What is the approximate resistance
of the load?
A. 0.083 ohm
B. 1.2 ohms
C. 12 ohms
D. 1200 ohms
Rationale: Using Ohm’s law, R = E/I. Therefore, 120 volts divided by 10
amperes equals 12 ohms.
3. What is the electrical power consumed by a 240-volt load drawing 15
amperes?
A. 225 watts
B. 1,600 watts
C. 3,600 watts
D. 5,760 watts
,Rationale: Electrical power in a simple resistive circuit can be calculated
using P = E × I. Therefore, 240 × 15 = 3,600 watts.
4. What is the primary function of a circuit breaker?
A. To increase circuit voltage
B. To provide continuous grounding-current flow
C. To automatically interrupt current when a circuit experiences an
overcurrent condition
D. To reduce normal operating current
Rationale: A circuit breaker protects conductors and equipment by opening
the circuit when current exceeds its designed rating or when another
qualifying trip condition occurs.
5. What is the primary purpose of a fuse?
A. To increase available fault current
B. To provide a permanent connection regardless of current
C. To open a circuit when excessive current causes the fuse element to
operate
D. To regulate normal voltage
, Rationale: A fuse contains a calibrated element designed to open the
circuit when excessive current causes it to melt or otherwise interrupt the
circuit. It provides overcurrent protection.
6. Which conductor is normally identified as the grounded conductor in a
typical 120/240-volt single-phase system?
A. Green
B. White or gray
C. Orange
D. Bare copper only
Rationale: The grounded circuit conductor is generally identified by white
or gray insulation or other permitted identification methods. Green and
bare conductors are generally associated with equipment grounding.
7. What is the primary purpose of an equipment grounding conductor?
A. To carry normal load current continuously
B. To increase branch-circuit voltage
C. To provide an effective path for fault current so protective devices can
operate
