Commercial Wiring Final Exam Questions with 100%
Answers 2025
Too many devices on one circuit could cause a type of overcurrent known as ______________ Correct
Answersoverload
A(n) ______________ occurs when there is a low-resistance path between conductors Correct
Answersshort circuit
A(n) ___________ is a short between a hot conductor and a grounding path Correct Answersground
fault
According to the Code, overcurrent protection devices must be ____________ Correct AnswersReadily
accessible and installed in a closure. Both A and B
Overcurrent protective devices are rated for _____________ Correct Answersamps and volts. Both A
and B
The highest fault current an OCPD is designed to handle is the device's ______________ rating Correct
Answersinterrupt
The two general types of fuses are plug and ______________ Correct Answerscartridge
A single-element fuse link(s) will melt in response to _________________ Correct Answersoverload
current
Time-delay fuses allow for___________ Correct Answersmomentary overloads
Edison-based fuses are ____________ Correct Answersinterchangeable
, Circuit breakers can be operated _______________ Correct Answerselectrically,manually,pneumatically.
All of the above
An inverse-time circuit breaker allows as much as __________ times the overload current before
opening the circuit Correct Answers10
The NEC _____________ rule allows a feeder conductor of smaller ampacity to be tapped without
overcurrent protection at the tap. Correct Answers10-foot tap
All electrical circuits are required to protect against overcurrent. Correct AnswersTrue
Typically, branch circuit overcurrent devices are located in the power panel. Correct AnswersTrue
Circuit breakers have to be replaced after they detect an overcurrent Correct AnswersFalse
The ampere rating of an overcurrent protection device is usually the same as the current-carrying
capacity of the circuit conductor Correct AnswersTrue
The fusible link can be replaced in renewable fuses Correct AnswersTrue
Cartridge fuses are used in circuits over 120 volts or over 30 amps Correct AnswersTrue
Single-element fuses are designed for circuits with transient surge currents. Correct AnswersFalse
Type S fuses must be used on all new installations and for replacement installations. Correct
AnswersTrue
The voltage rating of a fuse should never be lower than the circuit rating Correct AnswersTrue
Circuit breakers are NOT permitted to serve as a disconnecting switch Correct AnswersFalse
Answers 2025
Too many devices on one circuit could cause a type of overcurrent known as ______________ Correct
Answersoverload
A(n) ______________ occurs when there is a low-resistance path between conductors Correct
Answersshort circuit
A(n) ___________ is a short between a hot conductor and a grounding path Correct Answersground
fault
According to the Code, overcurrent protection devices must be ____________ Correct AnswersReadily
accessible and installed in a closure. Both A and B
Overcurrent protective devices are rated for _____________ Correct Answersamps and volts. Both A
and B
The highest fault current an OCPD is designed to handle is the device's ______________ rating Correct
Answersinterrupt
The two general types of fuses are plug and ______________ Correct Answerscartridge
A single-element fuse link(s) will melt in response to _________________ Correct Answersoverload
current
Time-delay fuses allow for___________ Correct Answersmomentary overloads
Edison-based fuses are ____________ Correct Answersinterchangeable
, Circuit breakers can be operated _______________ Correct Answerselectrically,manually,pneumatically.
All of the above
An inverse-time circuit breaker allows as much as __________ times the overload current before
opening the circuit Correct Answers10
The NEC _____________ rule allows a feeder conductor of smaller ampacity to be tapped without
overcurrent protection at the tap. Correct Answers10-foot tap
All electrical circuits are required to protect against overcurrent. Correct AnswersTrue
Typically, branch circuit overcurrent devices are located in the power panel. Correct AnswersTrue
Circuit breakers have to be replaced after they detect an overcurrent Correct AnswersFalse
The ampere rating of an overcurrent protection device is usually the same as the current-carrying
capacity of the circuit conductor Correct AnswersTrue
The fusible link can be replaced in renewable fuses Correct AnswersTrue
Cartridge fuses are used in circuits over 120 volts or over 30 amps Correct AnswersTrue
Single-element fuses are designed for circuits with transient surge currents. Correct AnswersFalse
Type S fuses must be used on all new installations and for replacement installations. Correct
AnswersTrue
The voltage rating of a fuse should never be lower than the circuit rating Correct AnswersTrue
Circuit breakers are NOT permitted to serve as a disconnecting switch Correct AnswersFalse
